Phylogenetic and ecological signals in the wood of Spathelioideae (Rutaceae) (original) (raw)
Related papers
Contributions to the Wood Anatomy of the Rubioideae (Rubiaceae
Journal of Plant Research, 2001
, Lasianthus, Saldinia, and Trichostachys are also included. Wood anatomical characters are compared with recent phylogenetic insights into the study group on the basis of molecular data. The observations demonstrate that the delimitation and separation of several taxa from the former Coussareeae/Morindeae/Prismatomerideae/Psychotrieae aggregate is supported by wood anatomical data. The Coussareeae can be distinguished from the other Rubioideae by their scanty parenchyma, septate libriform fibres, and the combination of uniseriate and very high multiseriate rays with sheath cells. Axial parenchyma bands and fibre-tracheids characterise Gynochtodes and some species of Morinda (Morindeae s.str.), but the latter genus is variable with respect to several features (e.g. vessel groupings and axial parenchyma distribution). Wood data support separation of Rennellia and Prismatomeris from Morindeae s.str.; vessels in both genera are exclusively solitary and axial parenchyma is always diffuse to diffuse-in-aggregates. Damnacanthus differs from the Morindeae alliance by the occurrence of septate fibres, absence of axial parenchyma, and the occasional presence of fibre wall thickenings. There are interesting similarities between members of the Lasianthus clade and the Pauridiantheae/Urophyleae group such as the sporadic occurrence of spiral thickenings in axial parenchyma cells.
A Survey of the Systematic Wood Anatomy of the Rubiaceae
IAWA Journal, 2002
Recent insight in the phylogeny of the Rubiaceae, mainly based on macromolecular data, agrees better with wood anatomical diversity patterns than previous subdivisions of the family. The two main types of secondary xylem that occur in Rubiaceae show general consistency in their distribution within clades. Wood anatomical characters, especially the fibre type and axial parenchyma distribution, have indeed good taxonomic value in the family. Nevertheless, the application of wood anatomical data in Rubiaceae is more useful in confirming or negating already proposed relationships rather than postulating new affinities for problematic taxa. The wood characterised by fibre-tracheids (type I) is most common, while type II with septate libriform fibres is restricted to some tribes in all three subfamilies. Mineral inclusions in wood also provide valuable information with respect to systematic relationships.
Comparative wood anatomy of Taxaceae
Comparative wood anatomy of Taxaceae s.l. was examined to elucidate the differences in wood features among genera. In total, 25 samples, comprising three varieties and seven species from five genera (Pseudotaxus was not included), were examined. Sliding microtome, wood maceration and scanning electron microscopy methods were used for the study. The growth rings are well developed and early and late wood are distinguishable in a cross-section. In general, there is remarkable uniformity in the characteristics of the five genera of Taxaceae, although some differences in quantitative traits were found. Wood of Taxaceae s.l. differs from that of most conifers by having helical thickening in the tracheid inner walls, with the exception of Austrotaxus spicata R.H.Compton. All genera are characterised by the absence of resin canals, predominantly uniseriate pits on the radial wall of the axial tracheids, and the presence of pits on the tangential walls of the axial tracheids. The rays are composed solely of parenchyma cells and are uniseriate (occasionally biseriate in Torreya nucifera (L.) Siebold et Zucc.), with a height of 1–22 cells. The genus Taxus shares more characteristics with Torreya than with Amentotaxus, Austrotaxus and Cephalotaxus. Correspondingly, Amentotaxus and Cephalotaxus resemble each other, marked by the presence of either diffuse or sparse axial parenchyma with nodulated transverse walls. Austrotaxus spicata is the sole species that lacks helical thickenings in the tracheid walls and has sparse axial parenchyma with smooth transverse walls. These two features, namely, the absence of helical thickenings and axial parenchyma with smooth transverse walls, are plesiomorphic and might be considered a more primitive character in wood anatomy. Among the other four genera, Amentotaxus appears to have an annular type of wall thickening that could be considered plesiomorphic to the spiral thickenings found in Taxus, Torreya and Cephalotaxus.
Lobostemon (Boraginaceae) comprises 28 shrubby species closely related to the herbaceous genus Echiostachys. Both are native to the Greater Cape Floristic Region of South Africa. Together, they form a sister clade to Echium, which is herbaceous except for 23 species that evolved into shrubs and rosette trees on the islands of Macaronesia. Lobostemon and woody Echium make a rare case of parallel evolution of woody habits from herbaceous ancestors (secondary woodiness) in climatically similar but geographically very distant areas. We examined the wood anatomy of 27 Lobostemon species and two of the three species of Echiostachys and compared it with the literature data on woody and herbaceous Echium. Despite differing growth habits, all species share similar wood anatomical traits that may reflect their preference for open, semi-arid habitats. Most conspicuously, there is a common tendency to retain ground tissue cells alive for prolonged periods. In woody species, this results in living fibres and fibre-tracheids. In herbs, it may lead to the total parenchymatization of wood that is devoid of dead cells, except for vessel elements. In Lobostemon, fibre-tracheids with conspicuous pits co-occur with grouped vessels. This may be related to the prolonged retention of protoplasts in ground tissue cells, which hinders water conductance, forcing the development of grouped vessels that can provide a bypass for water in case of embolism. We speculate that in Lobostemon, later-produced wood may contain dead fibre-tracheids and we expect to see less grouped vessels in such case. This potential ontogenetic shift in drought-coping mechanisms requires confirmation.
Wood anatomy of the Altingiaceae and Hamamelidaceae
Wood anatomical data for all three extant genera of the Altingiaceae and 23 of the 27 extant genera of the Hamamelidaceae were compiled in an effort to find features distinctive to genera, tribes, or subfamilies within these families. All genera studied have diffuse porous wood (except Corylopsis which tends to be semi-ring porous), vessels are predominantly solitary and narrow (<100 µm, usually < 50 µm) and angular in outline, vessel elements are long (> 800 µm) with scalariform perforation plates with average bar numbers of 9-44, intervessel pits are mainly scalariform to opposite, vessel-ray parenchyma pits are scalariform with slightly reduced borders and usually are in the square to upright marginal ray parenchyma cells, rays are heterocellular and narrow, usually 1-3-seriate. Although the wood anatomy of both families is relatively homogeneous, it is possible to key out many genera using a combination of qualitative (presence /absence and location of helical thickenings in vessel elements and fibers, crystal occurrence, axial parenchyma abundance, degree of ray heterogeneity) and quantitative features (number of bars per perforation plate and ray width). Helical thickenings are present throughout the vessel elements in three genera (Loropetalum, Altingia, Semiliquidambar) and are restricted to the vessel element tails in two genera (Corylopsis, Liquidambar). Loropetalum has helical thickenings in ground tissue fibers as well. Axial parenchyma abundance varies from scarce to relatively abundant diffuse to diffuse-in-aggregates. One clade of the tribe Fothergilleae (Distylium, Distyliopsis, Sycopsis, Shaniodendron, Parrotia, Parrotiopsis) has more abundant axial parenchyma and is characterized by narrow, usually interrupted bands of apotracheal parenchyma. Nearly exclusively uniseriate rays occur in some species of Hamamelis and in Exbucklandia, Chunia, Dicoryphe, and Fothergilla. These data on extant Altingiaceae and Hamamelidaceae not only provide information relevant for systematic, phylogenetic and ecological wood anatomy and wood identification, but also give context for reviewing the fossil woods assigned to them. A new combination is proposed for the Miocene Liquidambar hisauchii (Watari) Suzuki & Watari from Japan: Altingia hisauchii (Watari) Wheeler, Baas & Lee.
Review of Palaeobotany and Palynology
Fossil Taxaceae are documented for the Cenozoic throughout most of the northern hemisphere, but the pre-Cenozoic history of this group is still poorly known. The fossil wood record is difficult but can shed light on this history. We critically evaluated the fossil woods assigned to Taxaceae and then compared the fossil record of taxaceous woods to the fossil record of taxaceous leaves and reproductive structures. We then considered the fossil record in the context of family's molecular phylogeny. More than half of the fossil woods attributed to Taxaceae lack diagnostic characters of the family (longitudinal tracheids with helical thickenings and abietoid pitting on radial walls). Fossil wood that can be attributed to the fossil genus Taxaceoxylon, as well as some specimens placed in the genus Protelicoxylon, which differ only in having mixed type of intertracheary radial pitting, probably belong to Taxaceae. The fossil wood record, as reappraised, is not informative about the history of individual genera within the family, but fits that of leafy remains. Taxaceae wood shows remarkable resistance to embolism and subsequent increased risks of conduit implosion that might be prevented by the presence of tertiary helical thickenings. Our findings suggest a paleobiogeographical scenario for the Taxaceae, that involved a Western Europe Early Jurassic cradle and expansion to their Holarctic modern distribution.
Wood anatomy of the tribe Podalyrieae (Fabaceae, Papilionoideae): Diversity and evolutionary trends
South African Journal of Botany, 2013
Detailed wood anatomical data for 32 species from all nine genera of the tribe Podalyrieae are presented, together with numerical analyses and the mapping of character states onto the latest available molecular phylogeny. It was found that trees (Cadia, Calpurnia and Virgilia) have vessels in small isolated groups, whilst fynbos shrubs (the remaining genera: Amphithalea, Cyclopia, Liparia, Podalyria, Stirtonanthus and Xiphotheca) commonly show highly grouped narrow vessels (frequently in a dendritic pattern), and helical thickening on the vessel walls. Comparisons of the main character state changes with the molecular phylogeny of the tribe show that the wood structure of trees probably represents the basic condition in the tribe; character states present in shrubs appear to have arisen a few times and very likely represent adaptations to seasonal water stress. In general, the wood anatomy is congruent with current subtribal and generic delimitations. Fire-survival strategy is reflected in the rays, with seeders having mostly procumbent cells whilst sprouters have square and upright cells. The close similarity in wood anatomy between Cadia and Calpurnia is in agreement with the transfer of Cadia to the Podalyrieae. A remarkable diversity of crystals was found, including prismatic, acicular and navicular crystals, the last two of which may occur singly or in sheaf-like aggregates.
IAWA Journal, 1995
Stern and rhizome anatomy is reported for Anemopsis californica Hook., Houttuynia cordata Thunb., and Saururus cernuus L. Secondary growth is reported for the first time in Saururaceae. Cambia function indefinitely in Anemopsis in both fascicular and interfascicular areas. Interfascicular cambium is minimal in Saururus and absent in Houttuynia; fascicular cambium is present in both genera and produces a finite quantity of vessels, fiber-tracheids, and axial parenchyma but no rays. Anemopsis has vessels with simple perforation plates plus tracheids in wood, suggestive of adaptation to fluctuating water availability. The scalariform perforation plates of Houttuynia and Saururus suggest an unbroken history of occupancy of mesic habitats. Ethereal oil cells are reported for rays of Anemopsis, and for pith and cortex of the three genera studied. Stern idioblasts and other histologieal details are ineluded along with wood data in anatomical deseriptions of sterns. DNA data as weIl as maer...
Frontiers in Plant Science, 2023
In tropical and subtropical regions, much research is still required to explore the dendrochronological potential of their trees. This study aims to evaluate the anatomical structure and dendrochronological potential of three Mediterranean desert shrubs in Egypt (Lycium schweinfurthii var. schweinfurthii, L. europaeum, and Calligonum polygonoides subsp. comosum) supported by X-ray density. The results showed that the target species had distinct growth rings at macroscopic and microscopic levels. The vessel traits reflected the adaptability of each species with the prevailing arid climate conditions. After the exclusion of the noncorrelated series, we obtained three site chronologies that cover the years 2013-2022 for L. schweinfurthii, 2012-2022 for L. europaeum, and 2011-2022 for C. comosum. The mean series intercorrelation was 0.746, 0.564, and 0.683 for L. schweinfurthii, L. europaeum, and C. comosum, respectively. The EPS (expressed population signal) values ranged from 0.72 to 0.80, while the SNR (species-to-noise ratio) ranged from 9.1 to 21.5. Compiling all series of L. schweinfurthii raised the EPS value to 0.86. The chronologies developed for the studied species were relatively short since we dealt with multi-stemmed shrubs. The average percentage difference between latewood density (LWD) and earlywood density (EWD) in C. comosum, L. europaeum, and L. schweinfurthii were 11.8% ± 5.5, 5.2%± 1.87, and 3.6% ± 1.86, respectively. X-ray densitometry helped in the precise determination of the ring borders of the studied species. The relationships between the radial growth of the studied species and the climate variables were weak to moderate but mostly not significant (i.e., r < 0.7). Generally, the radial growth of the target species had a weak to moderate positive correlation with temperature and precipitation during the wet season (winter), while negatively correlated with temperature for the rest of the year, particularly in summer. Our data agrees with earlier findings that ring formation starts at the beginning of the long vegetative stage, then the rest of the assimilated carbohydrates are directed to the flowering and fruiting at the end Frontiers in Plant Science frontiersin.org 01