Dactyloctenium ctenoides (Steud.) Bosser

Gramineae, T. Cope. Flora Zambesiaca 10:2. 1999

Morphology General Habit

Spreading annual forming lax open mats; culms up to 50 cm tall, slender, ascending, prostrate below and rooting at the lower nodes; leaf laminas 4–13 cm × 3.5–7.5 mm, flat, papillose-hispid, sometimes sparsely so.

Morphology Reproductive morphology Inflorescences

Racemes 4–6, 1.4–3.3 cm long, narrowly oblong, stiffly ascending or radiating.

Morphology Reproductive morphology Inflorescences Spikelets

Spikelets 4–4.2 mm long, broadly ovate, 3–4-flowered; glumes unequal, the inferior 2–2.2 mm long, narrowly oblong in profile, narrowly winged and scabrid on the keel, the superior 1.7–2 mm long, oblong to narrowly obovate in profile, the keel extended into a stout awn 0.5–0.75 times as long as the body; lemmas 2.8–3.4 mm long, narrowly ovate in profile, the keel concave and scabrid above the middle, cuspidate at the apex; palea keels narrowly winged or sometimes almost wingless; anthers 0.4–0.6 mm long.

Morphology Reproductive morphology Fruits

Caryopsis 0.7–0.8 mm long, broadly obovate, finely granular-striate.

Extinction risk predictions for the world's flowering plants to support their conservation (2024). Bachman, S.P., Brown, M.J.M., Leão, T.C.C., Lughadha, E.N., Walker, B.E. https://nph.onlinelibrary.wiley.com/doi/full/10.1111/nph.19592

Conservation

Predicted extinction risk: not threatened. Confidence: confident

Morphology General Habit

Annual; mat forming. Culms decumbent, or prostrate; 20-50 cm long; rooting from lower nodes. Ligule an eciliate membrane. Leaf-blades 3.7-13 cm long; 3.5-7.5 mm wide. Leaf-blade margins tuberculate-ciliate. Leaf-blade apex acuminate.

Morphology Reproductive morphology Inflorescences

Inflorescence composed of racemes. Racemes (4-)5-6(-7); digitate; spreading, or ascending; oblong; unilateral; 1.4-3.3 cm long. Rhachis deciduous from axis; flattened; terminating in a barren extension; extension bristle-like. Spikelet packing broadside to rhachis; crowded; regular; 2 -rowed. Spikelets pectinate; solitary. Fertile spikelets sessile.

Morphology Reproductive morphology Inflorescences Spikelets

Spikelets comprising 3-4 fertile florets; with diminished florets at the apex. Spikelets ovate; laterally compressed; 4-4.2 mm long; breaking up at maturity; disarticulating above glumes but not between florets. Spikelet callus glabrous, or pubescent.

Fertile

Spikelets comprising 3-4 fertile florets; with diminished florets at the apex. Spikelets ovate; laterally compressed; 4-4.2 mm long; breaking up at maturity; disarticulating above glumes but not between florets. Spikelet callus glabrous, or pubescent.

Morphology Reproductive morphology Inflorescences Bracts Glume

Glumes persistent; dissimilar; shorter than spikelet. Lower glume oblong; 2-2.2 mm long; 1.1-1.2 length of upper glume; 1-keeled; winged on keel; winged narrowly; 1 -veined. Lower glume primary vein scabrous. Lower glume lateral veins absent. Lower glume apex acute. Upper glume elliptic; 1.7-2 mm long; 0.5-0.6 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume primary vein smooth. Upper glume lateral veins absent. Upper glume apex truncate; awned; 1 -awned. Upper glume awn subapical; 0.7-1.5 mm long.

Morphology Reproductive morphology Flowers Florets

Fertile florets appressed to rhachilla. Fertile lemma gibbous; ovate in profile; 2.8-3.4 mm long; membranous; keeled; 3 -veined. Lemma midvein scaberulous. Lemma lateral veins obscure. Lemma apex cuspidate; muticous. Palea 1 length of lemma; 2 -veined. Palea keels wingless, or winged; narrowly winged. Apical sterile florets resembling fertile though underdeveloped.

Morphology Reproductive morphology Flowers

Anthers 3; 0.4-0.6 mm long.

Morphology Reproductive morphology Fruits

Caryopsis with free soft pericarp; obovoid; 0.7-0.8 mm long; granular.

Distribution

Africa: east tropical, southern tropical, and western Indian ocean.

Reference

Eragrostideae. FTEA.

Diagnostic

Glume awn up to 0.75 length of body.