RBG Kew: GrassBase - Aegopogon

Description (original) (raw)

W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Aegopogon

HABIT Annual (4), or perennial (1). Culms erect (1), or geniculately ascending (1), or decumbent (3), or prostrate (1); slender (1/1); 4–18.7–40 cm long; without nodal roots (1/2), or rooting from lower nodes (2/2). Lateral branches sparse (1/1). Ligule an eciliate membrane (4), or a ciliolate membrane (1). Leaf-blades filiform (1), or linear (4); firm (2), or flaccid (3).

INFLORESCENCE Inflorescence composed of racemes.

Racemes borne along a central axis; spreading; cuneate; unilateral; bearing a triad of spikelets (4), or few fertile spikelets (1); bearing 2 fertile spikelets on each (1/1). Rhachis obsolete; deciduous from axis. Raceme-bases brief (2), or cuneate (3).

Spikelets in pairs (1), or in threes (4). Fertile spikelets sessile (2), or pedicelled (3); 1 in the cluster (4), or 2 in the cluster (1). Companion sterile spikelets pedicelled (4/4); 2 in the cluster (4/4). Pedicels linear (2), or oblong (3).

STERILE SPIKELETS Companion sterile spikelets absent (1), or well-developed (4); deciduous with the fertile (4/4). Companion sterile spikelet glumes muticous (1/4), or mucronate (1/4), or awned (3/4).

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; laterally compressed; 1.5–3.33–7.5 mm long; falling entire; deciduous with accessory branch structures.

GLUMES Glumes shorter than spikelet. Lower glume linear (1), or lanceolate (1), or obovate (1), or cuneate (3); 0.8–0.92–1 length of upper glume; membranous, or chartaceous (1); without keels; 1 -veined. Lower glume lateral veins absent. Lower glume surface smooth (4), or scabrous (1); without pits; glabrous (3), or pubescent (2). Lower glume apex entire (2), or lobed (3); 2 -fid (3/3); obtuse (2), or acute (1), or acuminate (2); muticous (2), or awned (4). Upper glume linear (1), or lanceolate (1), or obovate (1), or cuneate (3); 0.33–0.636–0.8 length of adjacent fertile lemma; membranous, or chartaceous (1); without keels; 1 -veined. Upper glume surface smooth (4), or scabrous (1); glabrous (3), or pubescent (2). Upper glume apex entire (2), or lobed (3); 2 -fid (3/3); obtuse (2), or acute (1), or acuminate (2); muticous (2), or awned (4); 1 -awned (4/4).

FLORETS Fertile lemma elliptic (2), or ovate (3); laterally compressed; lanceolate in profile (4/4); membranous, or chartaceous (1); keeled; wingless; 3 -veined. Lemma lateral veins without ribs (2), or ribbed (3). Lemma surface smooth (4), or scabrous (1); unwrinkled; without grooves; glabrous (3), or puberulous (1), or pubescent (1). Lemma apex lobed; 2 -fid (1), or 3 -fid (4); incised 0.1–0.2333–0.3 of lemma length; acute (1), or acuminate; awned; 1 -awned (1), or 3 -awned. Principal lemma awn apical (4), or from a sinus (1). Lateral lemma awns shorter than principal. Palea 1 length of lemma; 2 -veined. Palea keels separated (1), or contiguous above a sulcus (4). Palea surface glabrous (2), or puberulous (1), or pubescent (2). Palea apex dentate (4/4); with excurrent keel veins (1), or awned (4).

FLOWER Lodicules 2 (4/4); membranous (1/4), or fleshy (3/4). Anthers 3. Stigmas 2 (3/3). Ovary glabrous (1/1).

FRUIT Caryopsis with adherent pericarp (4/4); fusiform (2/2); isodiametric (2/2); biconvex (2/2); smooth (1/1); apex unappendaged (1/1). Embryo 0.3 length of caryopsis. Hilum punctiform (1/1).

DISTRIBUTION Tropical Asia (2), or North America (4), or South America (3).

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