GrassBase - The Online World Grass Flora

Descriptions

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

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

Aegopogon cenchroides

HABIT Annual; caespitose; clumped loosely. Culms decumbent; 4–20 cm long; 0.2–0.8 mm diam. Leaves cauline. Ligule an eciliate membrane; 1.3–2.3 mm long; lacerate. Leaf-blades 2–5 cm long; 1–1.7 mm wide; flaccid. Leaf-blade apex attenuate; filiform.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 15–25; borne along a central axis; spreading; cuneate; unilateral; 0.2–0.5 cm long; bearing a triad of spikelets. Central inflorescence axis 1–6 cm long. Rhachis obsolete; deciduous from axis. Raceme-bases cuneate; 2–3 mm long; pubescent; shed with the raceme; acute.

Spikelets in threes. Fertile spikelets pedicelled; 1 in the cluster; on shorter pedicels than sterile. Companion sterile spikelets pedicelled; 2 in the cluster. Pedicels oblong; semiterete; 0.5–1 mm long.

STERILE SPIKELETS Companion sterile spikelets well-developed; comprising 2 subequal glumes without lemmas, or containing empty lemmas, or male (vary from resembling fertile to rudimentary, the two spikelets often unequal); lanceolate; laterally compressed; 2–3 mm long; shorter than fertile; deciduous with the fertile. Companion sterile spikelet glumes membranous; 1–1.5 mm long; glabrous; lobed; 4 -fid; obtuse; awned; one glume awned; with 2–5 mm long awn. Companion sterile spikelet lemmas 1; exserted from glumes; 1–1.5 mm long; dentate; 1-awned; with 2 mm long awn.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; laterally compressed; 2–3 mm long; falling entire; deciduous with accessory branch structures.

GLUMES Glumes similar; shorter than spikelet. Lower glume cuneate; 2 mm long; 0.8 length of upper glume; membranous; without keels; 1 -veined. Lower glume lateral veins absent. Lower glume apex lobed; 2 -fid; acute; awned; 1 -awned. Lower glume awn 1–3 mm long. Upper glume cuneate; 0.7 length of adjacent fertile lemma; membranous; without keels; 1 -veined. Upper glume lateral veins absent. Upper glume apex lobed; 2 -fid; acute; awned; 1 -awned. Upper glume awn 1–3 mm long.

FLORETS Fertile lemma ovate; laterally compressed; lanceolate in profile; 2–3 mm long; membranous; dark brown; keeled; 3 -veined. Lemma lateral veins ribbed. Lemma apex lobed; 3 -fid; with outer lobes longer; with lanceolate lobes; incised 0.3 of lemma length; acuminate; awned; 3 -awned. Principal lemma awn 4–7 mm long overall; limb scaberulous. Lateral lemma awns arising on inner edge of lobes; 1–2 mm long; shorter than principal. Palea lanceolate; 1 length of lemma; 2 -veined. Palea keels contiguous above a sulcus. Palea apex dentate; 2 -fid; acute; awned; awns 0.5–2 mm long.

FLOWER Lodicules 2; cuneate; fleshy. Anthers 3; 2–2.2 mm long. Stigmas 2.

FRUIT Caryopsis with adherent pericarp; fusiform; isodiametric; biconvex; estipitate; without sulcus; 1.4 mm long; smooth; apex unappendaged. Embryo 0.3 length of caryopsis. Hilum punctiform. Endosperm farinose. Disseminule comprising a branch.

DISTRIBUTION Asia-tropical: Papuasia. North America: Mexico. South America: Mesoamericana, northern South America, and western South America.

NOTES Cynodonteae. WDC.

Please cite this publication as detailed in How to Cite Version: 3rd February 2016.