Cycads Research Papers - Academia.edu (original) (raw)

The influence of animals on patterns of seed dispersal has not been well explored, despite the importance of seed dispersal in plant population biology. Furthermore, the exploitation of animals as dispersal agents has been considered one... more

The influence of animals on patterns of seed dispersal has not been well explored, despite the importance of seed dispersal in plant population biology. Furthermore, the exploitation of animals as dispersal agents has been considered one reason for the replacement of gymnosperms by angiosperms in the Cretaceous. We studied seed dispersal in a cycad, Macrozamia riedlei, and showed that in the absence of animals, ripe seeds drop directly beneath the parent not more than 40 cm from the base. Several animals eat the fleshy outer integument of the seeds, and possums (Trichosurus vulpecula), transport seeds up to 24 m from the parent. The postdispersal positioning of seeds gave a log density-log distance relationship of y = 7.20 – 2.85x (r2= 0.96, N = 17). Effective local dispersal may have contributed to the persistence of cycads in the world flora for the last 200 million years.

This article addresses the cultural heritage and, thereby, socio-historical perception of the sotetsu plant (cycas revoluta) in Tokunoshima, the Amami islands and the broader Ryukyu archipelago of southern Japan. The article addresses the... more

This article addresses the cultural heritage and, thereby, socio-historical perception of the sotetsu plant (cycas revoluta) in Tokunoshima, the Amami islands and the broader Ryukyu archipelago of southern Japan. The article addresses the plant’s function as an emergency/resilience food resource, a field windbreak, a defining feature of a particular ‘cultural landscape’ and a potent symbol within Ryukyu history. While the Amami islands are (now) part of Japan, the article views them from a Pacific history viewpoint, as an underdeveloped archipelagic annex to a major, densely-populated regional power and whose
use of botanical and other primary resources has much in common with the islands of Oceania, not the least in terms of the “derivative vulnerabilities” (Lewis, 2009) arising from
Amami’s history of colonial disruption and economic exploitation. The discussions advanced in the article engage with the sotetsu’s nature as a food source, a progenitor of related ‘foodways’ and its complex role in the cultural landscape and heritage of the Amami islands and, in particular, southern Tokunoshima. The concluding section considers the heritage value and context of the plant and of the distinctive hedged ‘fieldscapes’ within the context of contemporary economic development.

Cycads (Cycadales) are an ancient order of gymnosperm, one family of which is endemic to Mexico. Historically, although never domesticated, in ancient Mesoamerica and modern Mexico they have played a significant role in regional... more

Cycads (Cycadales) are an ancient order of gymnosperm, one family of which is endemic to Mexico. Historically, although never domesticated, in ancient Mesoamerica and modern Mexico they have played a significant role in regional agroecology, and indigenous foodways, cultural practices, and beliefs. As a botanical resource that occurs in tropical and subtropical regions, cycads in Mesoamerica are used in a variety of ways and figure prominently in regional cultural traditions, in which they often possess a close relationship with maize. This contribution speaks
to this under appreciated, now often critically endangered plant. A critical heritage perspective that considers the rhizomatic networks and indigenous epistemologies
within which these plants are imbricated allows for the fuller consideration of a series of key issues that span multiple disciplines, including archaeology, ethnography,
human geography, and art history. Preliminary results of an on-going interdisciplinary research project are shared with the aim to stimulate further discussion on the significance of cycads in Mesoamerican beliefs, foodways, and ecology. We suggest that a closer examination of cycad-human relationships has the potential to motivate conservation of these endangered plants in ways that engage local communities and work to highlight the environmental and cultural role of cycads, as well as the significance of ancient and modern cultural practices that incorporate this natural cultural hybrid.

In 2007 Bonta and Osborne published 'Cycads in the vernacular: A compendium of local names', in which they concluded that, in contrast to other cycads around the world, very few names and meanings had been documented for Australian... more

In 2007 Bonta and Osborne published 'Cycads in the vernacular: A compendium of local names', in which they concluded that, in contrast to other cycads around the world, very few names and meanings had been documented for Australian Macrozamia species. This paper aims to better document the cycad species utilised by Aboriginal people for the benefit of researchers in diverse disciplines. It draws on information contained in primary sources and many early historic documents to present Aboriginal names and meanings for various species of Bowenia, Lepidozamia and Macrozamia in Australia, to clarify the names of some Australian species, and to provide additional names for species and plant components not included in the compendium. In addition, it compares patterns in the meanings of names in Australia to those used overseas, finding similarities and differences. By providing a more comprehensive synthesis of information on Indigenous names and meanings of these three genera, the paper demonstrates that the gap identified by Bonta and Osborne is more apparent than real, and highlights the value of cross-disciplinary collaboration in ethnohistorical, ethnobotanical, linguistic, anthropological and archaeological research.

Background: This study documents cycad-human relationships in Mexico, Belize, Guatemala, El Salvador, and Honduras over the last 6000 years. The impetus was acute need for a better understanding of previously undocumented uses of cycads... more

Background: This study documents cycad-human relationships in Mexico, Belize, Guatemala, El Salvador, and Honduras over the last 6000 years. The impetus was acute need for a better understanding of previously undocumented uses of cycads in this region, and the need to improve cycad conservation strategies using ethnobotanical data. We hypothesized that cycads are significant dietary items with no long-term neurological effects, are important to religious practice, and contribute to cultural identity and sense of place, but that traditional knowledge and uses are rapidly eroding. Guiding questions focused on nomenclature, food and toxicity, relationships to palms and maize, land management issues, roles in religious ceremony, and medicinal uses, among others, and contributions of these to preservation of cycads.

The epidermal anatomy of Pseudoctenis samchokense is described revealing non−bennettitalean characters of these leaves from the Permo−Carboniferous of China (and Korea). The specimens were originally described as Pterophyllum samchokense... more

The epidermal anatomy of Pseudoctenis samchokense is described revealing non−bennettitalean characters of these leaves from the Permo−Carboniferous of China (and Korea). The specimens were originally described as Pterophyllum samchokense suggesting a bennettitalean affinity. They can no longer be considered bennettitalean since their cuticles lack the distinctive brachyparacytic stomata of that clade. Pterophyllum was originally erected as a morphogenus for segmented leaves from the Mesozoic and has subsequently been clearly assigned to the Bennettitales. The segmented leaves from the Permo−Carboniferous of Shanxi and Hebei, China described herein require a new ordinal and generic assignment since the non−bennettitalean cuticular characters documented reinforce the uncertainties in attribution of any foliage older than Late Triassic to the Bennettitales. Based on leaf−architecture and epidermal anatomical characters, the specimens are at best assigned to the cycadalean genus Pseudoctenis. This genus was formerly known only from Mesozoic rocks. Consequently, the specimens are highly significant, as they are among the oldest known vegetative remains of cycads. Re-evaluation of the affinities of all specimens assigned to Pterophyllum from Palaeozoic rocks is thus essential. Based on a review of other Permian–Carboniferous fossil leaves assigned to Pterophyllum, we conclude that none yet reveals definitive bennettitalean characters.

Most knowledge concerning Mesozoic Era floras has come from compression fossils. This has been augmented in the last 20 years by rarer permineralized material showing cellular preservation. Here, we describe a new genus of anatomically... more

Most knowledge concerning Mesozoic Era floras has come from compression fossils. This has been augmented in the last 20 years by rarer permineralized material showing cellular preservation. Here, we describe a new genus of anatomically preserved gymnosperm seed from the Callovian–Oxfordian (Jurassic) Oxford Clay Formation (UK), using a combination of traditional sectioning and synchrotron radiation X-ray micro-tomography (SRXMT). Oxfordiana motturii gen. et sp. nov. is large and bilaterally symmetrical. It has prominent external ribs, and has a three-layered integument comprising: a narrow outer layer of thick walled cells; a thick middle parenchymatous layer; and innermost a thin fleshy layer. The integument has a longitudinal interior groove and micropyle, enveloping a nucellus with a small pollen chamber. The large size, bilateral symmetry and integumentary groove demonstrate an affinity for the new species within the cycads. Moreover, the internal groove in extant taxa is an autapomorphy of the genus Cycas, where it facilitates seed germination. Based upon the unique seed germination mechanism shared with living species of the Cycadaceae, we conclude that O. motturii is a member of the stem-group lineage leading to Cycas after the Jurassic divergence of the Cycadaceae from other extant cycads. SRXMT—for the first time successfully applied to fossils already prepared as slides—reveals the distribution of different mineral phases within the fossil, and allows us to evaluate the taphonomy of Oxfordiana. An early pyrite phase replicates the external surfaces of individual cells, a later carbonate component infilling void spaces. The resulting taphonomic model suggests that the relatively small size of the fossils was key to their exceptional preservation, concentrating sulfate-reducing bacteria in a locally closed microenvironment and thus facilitating soft-tissue permineralization.

This paper describes the significance of the arborescent cycad ‘‘tiusinte’’ to Honduran culture. Dioon mejiae is a wild food that supplements maize-bean diets for an estimated 33,000 indigenous and mestizo Hondurans. Female cones are... more

This paper describes the significance of the arborescent cycad
‘‘tiusinte’’ to Honduran culture. Dioon mejiae is a wild food that supplements
maize-bean diets for an estimated 33,000 indigenous and mestizo Hondurans.
Female cones are harvested for their seeds, which are processed and made into tamales, tortillas, and other products. Leaves are used for a variety of Catholic celebrations; minor uses of the leaves and female cone parts also persist. Tiusintes, a common-property resource, are being destroyed by the adverse effects of timber extraction, pastoralism, and swidden agriculture. However, traditional tiusinte protection schemes are still practiced, and these may provide the germ of a more comprehensive conservation policy for the species.

Se estudió la genética de las poblaciones naturales de Zamia furfuracea L. f. (Zamiaceae, Cycadales), una especie endémica al estado de Veracruz, México. Para ello se trabajó con cinco poblaciones utilizando la técnica de electroforesis... more

Se estudió la genética de las poblaciones naturales de Zamia furfuracea L. f. (Zamiaceae, Cycadales), una especie endémica al estado de Veracruz, México. Para ello se trabajó con cinco poblaciones utilizando la técnica de electroforesis en geles de almidón para obtener los estimadores de la diversidad genética, donde el número promedio de alelos por locus fue de 1.72, el polimorfismo promedio fue 97.8% y la heterocigosis esperada promedio fue 0.3313. Respecto a la estructura genética, se detectó exceso de homocigotos en todas las poblaciones, indicando pérdida de variabilidad genética por efecto de la endogamia. La diferenciación genética fue relativamente alta (~16%), por lo que la mayor parte de variación genética se debe a las diferencias entre poblaciones. No existió relación alguna entre las distancias genéticas y geográficas entre pares de poblaciones. También, se hizo un diagnóstico de su estado de conservación genético, indicando que hay una disminución importante de la diversidad genética, pero sus niveles son superiores al promedio de otras 26 especies de cícadas. Así su conservación se tendría que avocar a rescatar las cinco poblaciones, enfatizando aquellas que presentaron alelos exclusivos (i.e. Sontecomapan y Toro Prieto). Finalmente, es importante señalar que a pesar de que Zamia furfuracea, fue la primer cícada exportada al viejo mundo, este es uno de los primeros estudios donde se obtiene información con una base científica consistente, que se espera que sea un primer vértice de un triángulo que considere estudios demográficos, de interacciones ecológicas y de filogeografía utilizando marcadores moleculares, como DNA nuclear y de microsatélites.

"Cycads are globally one of the most threatened groups of plants, with 62 % of all species listed on the IUCN Red List (Nagalingum et al. 2011; IUCN 2011). The ongoing decline of cycad populations in India is not well documented as... more

"Cycads are globally one of the most threatened groups of plants, with 62 % of all species listed on the IUCN Red List (Nagalingum et al. 2011; IUCN 2011). The ongoing decline of cycad populations in India is not well documented as compared to other cycads of the world. Cycas pectinata Buchanan-Hamilton (Cycadaceae) is one of the most wide spread cycad is now under threat and its populations are declining at pace as compared to any other species of Cycas. In Northeast India, the cycad populations has shrunk to such an extent that it is almost at the verge of extinction from the region. In the present study, cycad population in Assam, Manipur, Sikkim, West Bengal, Arunachal Pradesh and Tripura were extensively surveyed in the field during 2007 to 2014. The paper highlights the current population status, range of distribution, phenology and threats to Cycas pectinata in Northeast India."

Las cícadas son uno de los grupos de plantas más amenazados de extinción en la actualidad, al mismo tiempo que son plantas llamativas para investigadores y coleccionistas por razones evolutivas y ornamentales principalmente. México es el... more

Las cícadas son uno de los grupos de plantas más amenazados de extinción en la actualidad, al mismo tiempo que son plantas llamativas para investigadores y coleccionistas por razones evolutivas y ornamentales principalmente. México es el segundo país en riqueza de cícadas en el mundo, en donde destaca la Sierra Madre Oriental por la riqueza y endemismos. El presente trabajo discute la distribución y el estatus de conservación de estas plantas en Hidalgo, situado al sur de esta sierra. Con base en revisiones en los principales herbarios del Hidalgo: Ceratozamia fuscoviridis Moore, Ceratozamia sabatoi Vovides, Vázq. Torres, Schutzman & Iglesias, Ceratozamia latifolia Miq., Ceratozamia mexicana Brongn., Dioon edule Lindl., Miq., Zamia loddigesii Miq., y Zamia vazquezii D.W. Stev., Sabato, A. Moretti & De Luca. Seis de estas especies tienen algún grado de amenaza de acuerdo a los criterios de la International Union for the Conservation of Nature (IUCN), destacando Ceratozamia fuscoviridis y Zamia vazquezii por estar en la categoría de "en peligro críti--Palabras clave: CESMO, conservación, rareza biológica, Sierra Madre Oriental, Zamiaceae.

Cycas circinalis var. orixensis Haines (Cycadaceae) is raised to species rank and a new species, Cycas nayagarhensis is described and illustrated from the state of Odisha in the northern Eastern Ghats of India. Both of these Odisha Cycas... more

Cycas circinalis var. orixensis Haines (Cycadaceae) is raised to species rank and a new species, Cycas nayagarhensis is described and illustrated from the state of Odisha in the northern Eastern Ghats of India. Both of these Odisha Cycas species described here, have characteristic megasporophylls having spinescent lateral teeth and a spear-like long apical spine. Male cones are the most peculiar in having
microsporophylls with upturned, one to variously forked apical spines. Cycas nayagarhensis is distinguished from C. orixensis by its massive arborescent stem, large male cones, with microsporophylls having entire or variously forked apical spine and radially compressed ovules. A comparative table of
the northern Eastern Ghats Cycas and a key to all the Indian species are provided. The infrageneric classification of the genus Cycas is modified and a new Subsection Orixenses under Section Cycas is created here to accommodate these two morphologically distinct endemic taxa from Odisha.

Mexico has the second largest cycad diversity in the world, and the Sierra Madre Oriental (SMO) is one of the richest biogeographic regions for these plants. Despite there is a general Cycad National Program in the country, there are no... more

Mexico has the second largest cycad diversity in the world, and the Sierra Madre Oriental (SMO) is one of the richest biogeographic regions for these plants. Despite there is a general Cycad National Program in the country, there are no state-level cycad conservation strategies or programs. Thus the aim of this study was to propose a cycad conservation strategy for the state of Hidalgo, which is located in the Southern part of the SMO. For this, a cycad species inventory was made in the state, for which three methods were used: review of published literature; consultation in the main Mexican herbaria to verify botanical specimens; and exhaustive field research to compare findings with previously reported species and to recognize new records at the county and state level. The proposed research work strategy combined the following elements: prioritize the county and local areas with greatest cycad species richness; prioritize the species least resistant to environmental change and/or having restricted geographic distribution; and to consider the main uses of these plants by local residents. The results showed that Hidalgo has three genera and eight species of cycads: Ceratozamia fuscoviridis, C. latifolia, C. mexicana, C. sabatoi, Dioon edule, Zamia fischeri, Z. loddigesii and Z. vazquezii, all of which are considered by the International Union for Conservation of Nature (IUCN). This study added two new species records for Hidalgo and 21 at the county level. The species are distributed in 26 counties, of which Chapulhuacán and Pisaflores are notable for their high species richness. Hidalgo has the fourth-greatest cycad species richness among Mexican states, although its area accounts for only 1.07% of the country. The state's diversity is greater than in other states with larger area, and even than in some other entire countries in Mesoamerica. The presented state cycad conservation strategy proposes that a total of some 11 325ha to be conserved in nine zones, including different vegetation types, distributed in seven counties. The strategy involves a mixed scheme that incorporates conservation in Protected Natural Areas (ANP), Small Farmer Reserves (Reservas Campesinas) and Environmental Management Units (UMA in Spanish). This proposal will be useful for government agencies to take into account in the process of designating land use for the Cloud Forest Biological Corridor (CBBMM in Spanish), a ANP in creation. The state of Hidalgo urgently needs a detailed analysis of trends in changes in vegetation cover and land use, and demographic studies of the cycads. It is recommended that the implementation phase of this state strategy be carried out jointly with local communities, academia, and state and federal agencies responsible for biodiversity conservation. Rev. Biol. Trop. 61 (3): 1119-1131. Epub 2013 September 01.

Background: This study documents cycad-human relationships in Mexico, Belize, Guatemala, El Salvador, and Honduras over the last 6000 years. The impetus was acute need for a better understanding of previously undocumented uses of cycads... more

Background: This study documents cycad-human relationships in Mexico, Belize, Guatemala, El Salvador, and Honduras over the last 6000 years. The impetus was acute need for a better understanding of previously undocumented uses of cycads in this region, and the need to improve cycad conservation strategies using ethnobotanical data. We hypothesized that cycads are significant dietary items with no long-term neurological effects, are important to religious practice, and contribute to cultural identity and sense of place, but that traditional knowledge and uses are rapidly eroding. Guiding questions focused on nomenclature, food and toxicity, relationships to palms and maize, land management issues, roles in religious ceremony, and medicinal uses, among others, and contributions of these to preservation of cycads. Methods: From 2000 to 2017, the authors conducted 411 semi-structured ethnographic interviews, engaged in participant-observation in Mexican and Honduran communities, and carried out archival research and literature surveys. Results: We documented 235 terms and associated uses that 28 ethnic groups have for 57 species in 19 languages across 21 Mexican states and 4 Central American nations. Carbohydrate-rich cycads have been both famine foods and staples for at least six millennia across the region and are still consumed in Mexico and Honduras. Certain parts are eaten without removing toxins, while seed and stem starches are detoxified via several complex processes. Leaves are incorporated into syncretic Roman Catholic-Mesoamerican religious ceremonies such as pilgrimages, Easter Week, and Day of the Dead. Cycads are often perceived as ancestors and protectors of maize, revealing a close relationship between both groups. Certain beliefs and practices give cycads prominent roles in conceptions of sense of place and cultural heritage. Conclusions: Cycads are still used as foods in many places. Though they do not appear to cause long-term neurological damage, their health effects are not fully understood. They are often important to religion and contribute to cultural identity and sense of place. However, because most traditional knowledge and uses are rapidly eroding, new community-based biocultural conservation efforts are needed. These should incorporate tradition where possible and seek inspiration from existing successful cases in Honduras and Mexico.

Zamia furfuracea L. f. is endemic cycad species from Veracruz, México. The species is dioecious cycad, which is endangeder. There is no report about the existence of a sexual dimorphism in this species, so it is not possible to perform... more

Zamia furfuracea L. f. is endemic cycad species from Veracruz, México. The species is dioecious cycad, which is endangeder. There is no report about the existence of a sexual dimorphism in this species, so it is not possible to perform adequate gender identification in early stages or when there is no strobili. A total of nine morphological variables were evaluated in 31 male an 26 female plants of a natural population of Veracruz to determine differences related to the gender of Z. furfuracea. Number of pair of leaves, leaf width, average width of leaflet and diameter of the petiole were significantly different between gender (P = 0.043, P = 0.032, P = 0.041 and P = 0.002, respectively). These characteristics may form morphometric markers to determine with greater certainty the gener ratio in this species.

This paper describes the significance of the arborescent cycad ''tiusinte'' to Honduran culture. Dioon mejiae is a wild food that supplements maize-bean diets for an estimated 33,000 indigenous and mestizo Hondurans. Female cones are... more

This paper describes the significance of the arborescent cycad ''tiusinte'' to Honduran culture. Dioon mejiae is a wild food that supplements maize-bean diets for an estimated 33,000 indigenous and mestizo Hondurans. Female cones are harvested for their seeds, which are processed and made into tamales, tortillas, and other products. Leaves are used for a variety of Catholic celebrations; minor uses of the leaves and female cone parts also persist. Tiusintes, a common-property resource, are being destroyed by the adverse effects of timber extraction, pastoralism, and swidden agriculture. However, traditional tiusinte protection schemes are still practiced, and these may provide the germ of a more comprehensive conservation policy for the species.

The endemic species Dioon sonorense comprises the northernmost group of populations of Dioon, in Sonora, Mexico. Although it is endangered, only the southern populations are protected within a preservation area, while the remaining... more

The endemic species Dioon sonorense comprises the northernmost group of populations of Dioon, in Sonora, Mexico. Although it is endangered, only the southern populations are protected within a preservation area, while the remaining populations have not been taken into account in management plans or genealogical studies. Describing the intraspecifi c genealogy and the geographical structure of the genetic variation of D. sonorense may help in the identifi cation of units for further conservation. Therefore, the main objective of this study was to describe the intraspecifi c genealogy of populations throughout the range of distribution of the endangered species D. sonorense, using haplotypes of the trnL-F spacer of the cpDNA. In addition, the levels of diversity of the employed molecular marker were estimated. Low levels of variability were recorded and at least two evolutionary units, corresponding to each haplotype, were identifi ed as components of the species. The inclusion of northern populations into conservation programs is recommended. In order to integrate these fi ndings to the genealogy of genus Dioon, trnL-F sequences of all the remaining species were merged and analyzed. An ancestral haplotype with wide distribution was detected in several species and one haplotype in D. sonorense was found shared with its sister species, D. tomasellii. This work represents a fi rst attempt to reconcile a genealogical approach in the identifi cation of important centers of genetic diversity of Mexican cycads. Resumen: La especie endémica Dioon sonorense representa el grupo de poblaciones más norteño para el género Dioon, en So-nora, México. A pesar de su estatus en peligro de extinción, sólo las poblaciones del sur están protegidas dentro de un área de conservación, mientras que las poblaciones restantes no han sido consideradas en los planes de manejo o en estudios genealógicos. La descripción de la genealogía intraespecífi ca y la estructura geográfi ca de la variación genética de D. sonorense puede ayudar en la identifi cación de unidades evolutivas para su posterior conservación. Por lo tanto, el objetivo principal de este estudio fue describir la genealogía intraespecífi ca de las poblaciones de D. sonorense a lo largo de su rango de distribución, usando los haplo-tipos del espacio trnL-F del ADNcp. Además, se estimaron los niveles de diversidad genética usando este marcador molecular. Se obtuvieron niveles bajos de variabilidad y se identifi caron al menos dos unidades evolutivas, correspondientes a cada haplotipo que componen a la especie. Se recomienda la inclusión de las poblaciones del norte en los programas de conservación. Con el fi n de integrar estos hallazgos en el contexto de la genealogía del género Dioon, las secuencias del espacio trnL-F de todas las especies restantes fueron combinadas y analizadas. Se detectó un haplotipo ancestral con una amplia distribución en varias especies y un ha-plotipo en D. sonorense se encontró compartido con su especie hermana, D. tomasellii. Este trabajo representa un primer intento de reconciliar un enfoque genealógico con la identifi cación de centros importantes de diversidad genética en las cícadas mexicanas. Palabras clave: ADN del cloroplasto, Dioon sonorense, especie en peligro de extinción, genética de la conservación.

""Male cones of Ixostrobus hailarensis from Lower Cretaceous strata of the Hailar region of north-east China were reexamined for features of their cuticle and in situ pollen. The cones are loosely aggregated and possess helically arranged... more

""Male cones of Ixostrobus hailarensis from Lower Cretaceous strata of the Hailar region of north-east China were reexamined for features of their cuticle and in situ pollen. The cones are loosely aggregated and possess helically arranged peltate microsporophylls containing resin bodies. Microsporophyll cuticle is thick, papillate and has elliptical stomata with 6–9 subsidiary and ∼10 encircling cells. Adaxial sporangia contain monosulcate pollen assignable to the dispersed taxon Cycadopites minimus. Both the cuticle and pollen are distinct from Ixostrobus but are consistent with the cycad genera Androstrobus, Aegianthus, Loricanthus and the putative angiosperm Solaranthus. Reanalysis of the type species of Androstrobus, A. zamioides, provides new information on its structure and allows an accurate delimitation of the genus and improved comparison with other genera. A new genus, Schimperstrobus, is erected for species now excluded from Androstrobus. Comparisons indicate that Solaranthus represents a male cycad cone and that Aegianthus, Loricanthus and Solaranthus are synonyms; Aegianthus has nomenclatural priority. We emend the combined generic and specific diagnoses for Aegianthus sibiricus to allow additional species to be placed in the genus, and erect the new combinations Aegianthus resinifera for specimens previously assigned to Loricanthus, and Aegianthus daohugouensis for specimens previously placed within Solaranthus. The Hailar cone conforms to the generic circumscription of Aegianthus and represents a new species that we name A. hailarensis comb. nov. Androstrobus phialophora also conforms with Aegianthus and is transferred to Aegianthus phialophora comb. nov. Co-occurring with A. hailarensis are cuticles of the ginkgophyte leaf Sphenobaiera longifolia that are similar to microsporophyll cuticles of A. hailarensis. However, we discount that they belong to a single plant species and conclude that the cuticles of some Mesozoic ginkgoalean and cycadalean taxa may be virtually indistinguishable. We consider that Aegianthus was widespread across China, Mongolia and southern Russia during the Upper Jurassic to Lower Cretaceous.""

Background: Even if they are considered the quintessential " living fossils " , the fossil record of the extant genera of the Cycadales is quite poor, and only extends as far back as the Cenozoic. This lack of data represents a huge... more

Background: Even if they are considered the quintessential " living fossils " , the fossil record of the extant genera of the Cycadales is quite poor, and only extends as far back as the Cenozoic. This lack of data represents a huge hindrance for the reconstruction of the recent history of this important group. Among extant genera, Bowenia (or cuticles resembling those of extant Bowenia) has been recorded in sediments from the Late Cretaceous and the Eocene of Australia, but its phylogenetic placement and the inference from molecular dating still imply a long ghost lineage for this genus. Results: We reexamine the fossil foliage Almargemia incrassata from the Lower Cretaceous Anfiteatro de Ticó Formation in Patagonia, Argentina, in the light of a comparative cuticular analysis of extant Zamiaceae. We identify important differences with the other member of the genus, viz. A. dentata, and bring to light some interesting characters shared exclusively between A. incrassata and extant Bowenia. We interpret our results to necessitate the erection of the new genus Eobowenia to accommodate the fossil leaf earlier assigned as Almargemia incrassata. We then perfom phylogenetic analyses, including the first combined morphological and molecular analysis of the Cycadales, that indicate that the newly erected genus could be related to extant Bowenia.

The first permineralized cycad pollen cone is described from the Lower Middle Triassic of Antarctica. The cone is characterized by helically arranged, wedge-shaped microphylls, each with five or more spinelike projections extending from... more

The first permineralized cycad pollen cone is described from the Lower Middle Triassic of Antarctica. The cone is characterized by helically arranged, wedge-shaped microphylls, each with five or more spinelike projections extending from the rhomboid distal face. The vascular cylinder is dissected and produces paired traces to each microsporophyll. Three vascular bundles enter the base of the microsporophyll and divide to produce at least five vascular strands in the sporophyll lamina. Pollen sacs occur in two radial clusters near the lateral margins on the abaxial surface of the microsporophyll. Each cluster bears up to eight elongate pollen sacs that are fused for approximately half their length and display longitudiinal dehiscence. Pollen sacs are sessile and attached to a vascularized, receptacle-like pad of tissue that is raised from the surface of the microsporophyll. Pollen is ovoid, psilate, and monosulcate. Although the affinities of this cone with the Cycadales are obvious, the complement of characters in the fossil is unique and thus does not permit assignment to an extant family. Features of the cone are evaluated against reproductive aspects of living cycads.

The cycads are remnants of a flora that dominated the terrestrial ecosystems across the Mesozoic Era. The stem record of fossil cycads is scanty, with seventeen genera described around the world. From them, eight come from Argentina... more

The cycads are remnants of a flora that dominated the terrestrial ecosystems across the Mesozoic Era. The stem record of fossil cycads is scanty, with seventeen genera described around the world. From them, eight come from Argentina (Triassic to Paleogene strata), and actually six from the Cretaceous of Patagonia. In this research, we present a new fossil trunk of cycad from Upper Cretaceous beds of Patagonia. The good preservation of the permineralized stem allows to make detailed descriptions and comparisons and, accordingly, support the erection of a new taxon, Zamuneria amyla gen. et sp. nov. This new taxon possesses characters that fit with the Encephalarteae (e.g., columnar stem with persistent leaf bases and cataphylls, a wide pith, medullary vascular bundles, mucilage canals and idioblasts, a polyxylic vascular cylinder). Some features present in Zamuneria are discussed, such as the great development of parenchyma tissues with a marked amount of specialized cells (idioblasts), probably related with some protective function. Furthermore, the presence of cycads during the deposition of the Mata Amarilla Formation allows inferring climatic conditions, as well as a greater diversity of Encephalarteae in South America reinforces the endemic conditions for this group for the Cretaceous of southern continents.

Entrevista realizada por la periodista Liz Yanira Del Valle a Jaime R. Pagán Jiménez

Pathological changes of the aging brain are expressed in a range of neurodegenerative disorders that will impact increasing numbers of people across the globe. Research on the causes of these disorders has focused heavily on genetics, and... more

Pathological changes of the aging brain are expressed in a range of neurodegenerative disorders that will impact increasing numbers of people across the globe. Research on the causes of these disorders has focused heavily on genetics, and strategies for prevention envision drug-induced slowing or arresting disease advance before its clinical appearance. We discuss a strategic shift that seeks to identify the environmental causes or contributions to neurodegeneration, and the vision of primary disease prevention by removing or controlling exposure to culpable agents. The plausibility of this approach is illustrated by the prototypical neurodegenerative disease amyotrophic lateral sclerosis and parkinson-ism-dementia complex (ALS-PDC). This often-familial long-latency disease, once thought to be an inherited genetic disorder but now known to have a predominant or exclusive environmental origin, is in the process of disappearing from the three heavily affected populations, namely Chamorros of Guam and Rota, Japanese residents of Kii Peninsula, Honshu, and Auyu and Jaqai linguistic groups on the island of New Guinea in West Papua, Indonesia. Exposure via traditional food and/or medicine (the only common exposure in all three geographic isolates) to one or more neurotoxins in seed of cycad plants is the most plausible if yet unproven etiology. Neurotoxin dosage and/or subject age at exposure might explain the stratified epidemic of neurodegenerative disease on Guam in which high-incidence ALS peaked and declined before that of PD, only to be replaced today by a dementing disorder comparable to Alzheimer's disease. Exposure to the Guam environment is also linked to the delayed development of ALS among a subset of Chamorro and non-Chamorro Gulf War/Era veterans, a summary of which is reported here for the first time. Lessons learned from this study and from 65 years of research on ALS-PDC include the exceptional value of initial, field-based informal investigation of disease-affected individuals and communities, the results of which can provide an invaluable guide to steer cogent epidemiological and laboratory-based research. ã 2016 Elsevier Inc. All rights reserved. " Health planners in developed countries are increasingly concerned with their burgeoning populations of elderly subjects and the consequent rising prevalence of age-associated disorders, notably those involving the nervous system. By the year 2050, current projections for the United States indicate that the proportion of the population aged 65 or over will be almost double (22%) the 1986 level, whereas the prevalence of senile dementia of the Alzheimer type will triple. It is thus entirely appropriate for the elderly of developed countries to be the subjects of intense scientific scrutiny aimed at understanding the causes and methods of prevention of the major neurodegenerative diseases that all too often accompany the second half of life. There are certain other parts of the world, however, notably in the western Pacific region, where such disorders are far more commonly encountered and where prospecting for etiology is more likely to be profitable. Indeed, one would posit that a knowledgeable extraterrestrial investigator, charged with the task of identifying causes of the great neurodegenerative diseases of Homo sapiens on planet Earth, would be unlikely to begin by researching elderly populations in Canberra, London, or New York; rather, the hunt for causation would probably commence in places such as Guam or Irian Jaya [West Papua] where, in certain spots, incidence rates for such diseases have exceeded worldwide

The genus Dioon occupies an important phylogenetic position as sister to the other Zamiaceae. However, its epidermal morphology is still poorly known. We employed scanning and transmission electron microscopy, confocal microscopy and... more

The genus Dioon occupies an important phylogenetic position as sister to the other Zamiaceae. However, its epidermal morphology is still poorly known. We employed scanning and transmission electron microscopy, confocal microscopy and light microscopy to examine the epidermal and cuticular morphology of 12 of the 14 currently recognized species of Dioon, examining cultivated plants and herbarium specimens. Epidermal characters separate Dioon quite clearly from the other genera of the cycads. Within the genus, the major subgroups can be distinguished by their epidermal morphology. Some characters, such as the degree of stomatal protection, reflect ecological specializations in species within the subgroups. Several epidermal characters of the crown group Dioon seem to be absent in the Cenozoic fossils usually associated with the genus, which have been used as calibrations in many recent molecular dating analyses. The presence of similar characters in a Mesozoic fossil adapted to volcanic stress offers a new key in the interpretation of Dioon evolution.

Background: This study documents cycad-human relationships in Mexico, Belize, Guatemala, El Salvador, and Honduras over the last 6000 years. The impetus was acute need for a better understanding of previously undocumented uses of cycads... more

Background: This study documents cycad-human relationships in Mexico, Belize, Guatemala, El Salvador, and Honduras over the last 6000 years. The impetus was acute need for a better understanding of previously undocumented uses of cycads in this region, and the need to improve cycad conservation strategies using ethnobotanical data. We hypothesized that cycads are significant dietary items with no long-term neurological effects, are important to religious practice, and contribute to cultural identity and sense of place, but that traditional knowledge and uses are rapidly eroding. Guiding questions focused on nomenclature, food and toxicity, relationships to palms and maize, land management issues, roles in religious ceremony, and medicinal uses, among others, and contributions of these to preservation of cycads. Methods: From 2000 to 2017, the authors conducted 411 semi-structured ethnographic interviews, engaged in participant-observation in Mexican and Honduran communities, and carried out archival research and literature surveys. Results: We documented 235 terms and associated uses that 28 ethnic groups have for 57 species in 19 languages across 21 Mexican states and 4 Central American nations. Carbohydrate-rich cycads have been both famine foods and staples for at least six millennia across the region and are still consumed in Mexico and Honduras. Certain parts are eaten without removing toxins, while seed and stem starches are detoxified via several complex processes. Leaves are incorporated into syncretic Roman Catholic-Mesoamerican religious ceremonies such as pilgrimages, Easter Week, and Day of the Dead. Cycads are often perceived as ancestors and protectors of maize, revealing a close relationship between both groups. Certain beliefs and practices give cycads prominent roles in conceptions of sense of place and cultural heritage. Conclusions: Cycads are still used as foods in many places. Though they do not appear to cause long-term neurological damage, their health effects are not fully understood. They are often important to religion and contribute to cultural identity and sense of place. However, because most traditional knowledge and uses are rapidly eroding, new community-based biocultural conservation efforts are needed. These should incorporate tradition where possible and seek inspiration from existing successful cases in Honduras and Mexico.

En Honduras se realiza anualmente la Feria del Teosinte. Esta es una planta perteneciente a las cícadas. La especie corresponde a Dioon mejiae, una de las cícadas de mayor altura en el mundo, pues puede llegar a medir al menos 10 m de... more

En Honduras se realiza anualmente la Feria del Teosinte. Esta es una planta perteneciente a las cícadas. La especie corresponde a Dioon mejiae, una de las cícadas de mayor altura en el mundo, pues puede llegar a medir al menos 10 m de altura.

Even if they are considered the quintessential "living fossils", the fossil record of the extant genera of the Cycadales is quite poor, and only extends as far back as the Cenozoic. This lack of data represents a huge hindrance... more

Even if they are considered the quintessential "living fossils", the fossil record of the extant genera of the Cycadales is quite poor, and only extends as far back as the Cenozoic. This lack of data represents a huge hindrance for the reconstruction of the recent history of this important group. Among extant genera, Bowenia (or cuticles resembling those of extant Bowenia) has been recorded in sediments from the Late Cretaceous and the Eocene of Australia, but its phylogenetic placement and the inference from molecular dating still imply a long ghost lineage for this genus. We re-examine the fossil foliage Almargemia incrassata from the Lower Cretaceous Anfiteatro de Ticó Formation in Patagonia, Argentina, in the light of a comparative cuticular analysis of extant Zamiaceae. We identify important differences with the other member of the genus, viz. A. dentata, and bring to light some interesting characters shared exclusively between A. incrassata and extant Bowenia. We int...

Question: What evidence is there for cycad–insect interactions in the fossil record? Organism: The pollen cone Delemaya spinulosa Klavins, Taylor, Krings et Taylor. Locality: Fremouw Formation (Middle Triassic), Fremouw Peak, Central... more

Question: What evidence is there for cycad–insect interactions in the fossil record? Organism: The pollen cone Delemaya spinulosa Klavins, Taylor, Krings et Taylor. Locality: Fremouw Formation (Middle Triassic), Fremouw Peak, Central Transantarctic Mountains, Antarctica. Methods: We document the presence of pollen-laden coprolites in pollen sacs of a Middle Triassic cycad. Conclusions: These coprolites are comparable with fecal pellets of modern arthropods and we suggest that they were produced by beetles. This provides the oldest unequivocal evidence for a cycad–insect interaction and may represent a precursory stage in the establishment of a more complex cycad–pollinator relationship.

Cycads and colobus monkeys occur together in many parts of tropical Africa; we present the first records of colobus feeding on these plants. On 22 occasions, the Endangered Zanzibar red colobus Procolobus kirkii fed on the leaves of... more

Cycads and colobus monkeys occur together in many parts of tropical Africa; we present the first records of colobus feeding on these plants. On 22 occasions, the Endangered Zanzibar red colobus Procolobus kirkii fed on the leaves of Encephalartos hildebrandtii, a Near Threatened species, in the Kiwengwa-Pongwe Forest Reserve, north-eastern Unguja. A total of 92 minutes of cycad feeding were observed during a 14-month, 678-hour study of three focal groups, suggesting rare but consistent use of cycads. We analyzed HCN content in a small sample of browsed and unbrowsed cycad leaves for a preliminary analysis of toxicity, but toxicity was similar (and high) across leaves. Colobus appear to be one of the few mammal species able to exploit this abundant food source (277 cycads/ha) in the 33 km2 coral rag forest. Both colobus and cycads of this region are in need of urgent protection; in August 2011, much tree cutting was observed resulting in a discontinuous canopy which will threaten the arboreal colobus and shade-germinating cycads.

Most knowledge concerning Mesozoic Era floras has come from compression fossils. This has been augmented in the last 20 years by rarer permineralized material showing cellular preservation. Here, we describe a new genus of anatomically... more

Most knowledge concerning Mesozoic Era floras has come from compression fossils. This has been augmented in the last 20 years by rarer permineralized material showing cellular preservation. Here, we describe a new genus of anatomically preserved gymnosperm seed from the Callovian–Oxfordian (Jurassic) Oxford Clay Formation (UK), using a combination of traditional sectioning and synchrotron radiation X-ray micro-tomography (SRXMT). Oxfordiana motturii gen. et sp. nov. is large and bilaterally symmetrical. It has prominent external ribs, and has a three-layered integument comprising: a narrow outer layer of thick walled cells; a thick middle parenchymatous layer; and innermost a thin fleshy layer. The integument has a longitudinal interior groove and micropyle, enveloping a nucellus with a small pollen chamber. The large size, bilateral symmetry and integumentary groove demonstrate an affinity for the new species within the cycads. Moreover, the internal groove in extant taxa is an aut...

Premise of research. Many Ceratozamia species are closely related and form species complexes with great similarity among the component taxa, especially in juvenile stages. This, coupled with character loss in herbarium specimens, has... more

Premise of research. Many Ceratozamia species are closely related and form species complexes with great similarity among the component taxa, especially in juvenile stages. This, coupled with character loss in herbarium specimens, has resulted in debate regarding recognition and validation of the species. This study, focused on the four species comprising the Ceratozamia norstogii species complex from a morphological and leaflet anatomy viewpoint, was undertaken to clarify relationships among the four taxa in the complex.

Premise of research. Many Ceratozamia species are closely related and form species complexes with great similarity among the component taxa, especially in juvenile stages. This, coupled with character loss in herbarium specimens, has... more

Premise of research. Many Ceratozamia species are closely related and form species complexes with great similarity among the component taxa, especially in juvenile stages. This, coupled with character loss in herbarium specimens, has resulted in debate regarding recognition and validation of the species. This study, focused on the four species comprising the Ceratozamia norstogii species complex from a morphological and leaflet anatomy viewpoint, was undertaken to clarify relationships among the four taxa in the complex.

Premise of research. Many Ceratozamia species are closely related and form species complexes with great similarity among the component taxa, especially in juvenile stages. This, coupled with character loss in herbarium specimens, has... more

Premise of research. Many Ceratozamia species are closely related and form species complexes with great similarity among the component taxa, especially in juvenile stages. This, coupled with character loss in herbarium specimens, has resulted in debate regarding recognition and validation of the species. This study, focused on the four species comprising the Ceratozamia norstogii species complex from a morphological and leaflet anatomy viewpoint, was undertaken to clarify relationships among the four taxa in the complex.

The Australian endemic weevils of the genus Miltotranes Zimmerman, 1994 (Curculionidae: Molytinae: Tranes group), comprising two species, M. prosternalis (Lea, 1929) and M. subopacus (Lea, 1929), are highly host-specific and the only... more

The Australian endemic weevils of the genus Miltotranes Zimmerman, 1994 (Curculionidae: Molytinae: Tranes group), comprising two species, M. prosternalis (Lea, 1929) and M. subopacus (Lea, 1929), are highly host-specific and the only known pollinators of Bowenia cycads, which comprise two CITES-protected species restricted to Tropical Queensland in Australia. In the present study, the taxonomy of Miltotranes is reviewed, a lectotype for the name Tranes prosternalis Lea, 1929 is designated and a new species associated with the Bowenia population in the McIlwraith Range is described as M. wilsoni sp. n. The descriptions and diagnoses of all species are supplemented with illustrations of their habitus and salient structures, and an identification key to all species and a distribution map are provided. Potential implications of the new species and of the taxonomy and biogeography of Miltotranes overall on the systematics and conservation of Bowenia are discussed.

Antecedentes: Dioon angustifolium es una especie endémica que se distribuye en el extremonoreste de la Sierra Madre Oriental. Se clasifica como especie en peligro de extinción debido a actividades antrópicas como la extracción ilegal con... more

Antecedentes: Dioon angustifolium es una especie endémica que se distribuye en el extremonoreste de la Sierra Madre Oriental. Se clasifica como especie en peligro de extinción debido a actividades antrópicas como la extracción ilegal con fines comerciales.Pregunta: ¿Cuál es el estado actual de la estructura de las poblaciones de Dioon angustifolium en su área de distribución?Especie en estudio: Dioon angustifolium Miq. (Zamiaceae), especie endémica de la Sierra Madre Oriental en México.Lugar y años de estudio: El estudio se realizó en tres poblaciones de D. angustifolium en Nuevo León (DA1, DA2) y Tamaulipas (DA3) durante el verano de 2018Métodos: Se determinó la densidad y estructura poblacional de D. angustifolium mediante transectos de 100 m de largo. Para cada una de las poblaciones analizadas se construyó una tabla de vida estática.Resultados: La mayor densidad correspondió a la población DA1 y la menor a DA3. Esta última población está dominada por individuos en fase juvenil. ...

Ceratozamia fuscoviridis, or teosintle in nahuatl, is a recently rediscovered endangered cycad species previously known from only one population (Molango) in Sierra Madre Oriental of the State of Hidalgo, Mexico. Recent botanical... more

Ceratozamia fuscoviridis, or teosintle in nahuatl, is a recently rediscovered endangered cycad species previously known from only one population (Molango) in Sierra Madre Oriental of the State of Hidalgo, Mexico. Recent botanical explorations have found new but scattered populations, increasing its known geographical range. Ecological studies were conducted on six of the 29 populations found. Parameters such as size, density, population structure, and static life table are presented. This is the first study of its kind conducted to prompt the Mexican authorities to establish natural protected areas for this species and the associated biodiversity, because deforestation is rapidly diminishing the populations. The population structure in general showed a Deevey-III curve, while two populations showed Deevey-I curves. A 400 m2 area had a population size from 143 to 378 individuals. Population density varied from 0.358 individuals/m2 to 0.945 individuals/m2. Population structure was sta...

Cycad Aulacaspis Scale (Hemiptera: Diaspididae: Aulacaspis yasumatsui Takagi, 1977), which is native to Southeast Asia, is a devastating pest of some species of cycads in areas where it is invasive. In September 2016, it was reported to... more

Cycad Aulacaspis Scale (Hemiptera: Diaspididae: Aulacaspis yasumatsui Takagi, 1977), which is native to Southeast Asia, is a devastating pest of some species of cycads in areas where it is invasive. In September 2016, it was reported to be present in Chiapas in southern Mexico, a country with 60 native cycad species, most of which are endemic and endangered. Here we report the presence of the pest in 6 additional Mexican states and in Guatemala. Surveys of natural populations and quasi-natural sustainable nurseries in 4 states, including Chiapas, find no evidence that the pest has yet spread to natural populations. At present, it appears to be confined to cultivated cycads, presenting a window of opportunity for effective control.

Little is known about the adaptive value of mast seeding, a common phenomenon in temperate trees and shrubs. Masting is likely to affect both seed dispersal and seed predation. In systems where similar taxa of animals are involved in... more

Little is known about the adaptive value of mast seeding, a common phenomenon in temperate trees and shrubs. Masting is likely to affect both seed dispersal and seed predation. In systems where similar taxa of animals are involved in these two processes, the consequences of mast seeding are likely to be particularly complicated. This study examined the effects of mast seeding in a cycad, Macrozamia communis, on the dispersal of seeds, the pattern of dispersion of seeds and post-dispersal predation on seeds. Dispersal of seeds by possums was poorer from source plants in a masting population than from source plants in an adjacent, non-masting population. This resulted in fewer seeds per seeding female plant in the masting plot being dispersed to favourable sites. We conclude that this is caused by the feeding behaviour and movements of possums in the masting site. The abundance of seeds in this site did not satiate the post-dispersal predators, native rats. In fact, more seeds in this site were eaten than in the nonmasting site. We suggest that the mast seeding observed in M. communis may not be adaptive, but is more likely a consequence of other factors which synchromize flowering within local populations.