GrassBase - The Online World Grass Flora


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

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

Aegopogon tenellus

HABIT Annual; caespitose; clumped densely. Culms decumbent, or prostrate; 10–40 cm long; 0.2–0.8 mm diam.; without nodal roots, or rooting from lower nodes. Leaves cauline. Ligule an eciliate membrane. Leaf-blades 1.5–6 cm long; 0.5–1.5 mm wide; flaccid. Leaf-blade surface puberulous; hairy adaxially.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 15–25; borne along a central axis; spreading; cuneate; unilateral; 0.3–0.5 cm long; bearing a triad of spikelets. Central inflorescence axis 1–5 cm long. Rhachis obsolete; deciduous from axis. Raceme-bases brief; 0.5 mm long; pubescent.

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

STERILE SPIKELETS Companion sterile spikelets well-developed; containing empty lemmas; lanceolate; laterally compressed; 1.5–3.5 mm long; shorter than fertile; deciduous with the fertile. Companion sterile spikelet glumes membranous; glabrous; lobed; 2 -fid; obtuse; muticous, or mucronate. Companion sterile spikelet lemmas 1; exserted from glumes; muticous.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; laterally compressed; 2–4 mm long; falling entire; deciduous with accessory branch structures.

GLUMES Glumes similar; shorter than spikelet. Lower glume obovate, or cuneate; 1–2 mm long; 1 length of upper glume; membranous; without keels; 1 -veined. Lower glume lateral veins absent. Lower glume apex lobed; 2 -fid; obtuse; muticous, or awned; 1 -awned. Lower glume awn 0.2–1 mm long. Upper glume obovate, or cuneate; 1–2 mm long; 0.75 length of adjacent fertile lemma; membranous; without keels; 1 -veined. Upper glume lateral veins absent. Upper glume apex lobed; 2 -fid; obtuse; muticous, or awned; 1 -awned. Upper glume awn 0.2–1 mm long.

FLORETS Fertile lemma ovate; laterally compressed; lanceolate in profile; 2–4 mm long; membranous; keeled; 3 -veined. Lemma lateral veins ribbed. Lemma apex lobed; 3 -fid; with outer lobes longer; with lanceolate lobes; with lobes 0.5 mm long; incised 0.1–0.3 of lemma length; acuminate; awned; 1 -awned, or 3 -awned. Principal lemma awn 4–8(–11) mm long overall. Lateral lemma awns arising on inner edge of lobes; 0.5 mm long; shorter than principal. Palea lanceolate; 1 length of lemma; 2 -veined. Palea keels contiguous above a sulcus. Palea surface pubescent; hairy on back. Palea apex dentate; 2 -fid; acute; awned; awns 0.5–2 mm long.

FLOWER Lodicules 2; cuneate; fleshy. Anthers 3. Stigmas 2.

FRUIT Caryopsis with adherent pericarp. Disseminule comprising a branch.

DISTRIBUTION North America: southwest USA and Mexico. South America: Mesoamericana and northern South America.

NOTES Cynodonteae. Beetle.

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