Microstegium delicatulum (Hook.f.) A.Camus

Chen, H., Veldkamp, J. - F. & Kuoh, C. - S., 2012, Taxonomic revision of Microstegium s. str. Andropogoneae, Poaceae), Blumea 57 (2), pp. 160-189 : 164

3. Microstegium delicatulum (Hook.f.) A.Camus — Fig. 2 ; Map 3

Microstegium delicatulum (Hook.f.) A. Camus (1921) 200. — Pollinia delicatula Hook.f.(1896a) 117. — Type: Kurz 1204 (holo K), designated by Bor (1952).

Annuals, mat-forming. Culms rambling, weak, 30–90 cm long, rooting from the lower nodes. Nodes bearded. Sheaths glabrous, outer margin glabrous, oral hairs absent. Ligule a glabrous membrane, 0.2–0.5 mm long. Blades elliptic, 5–10 cm by 4–8 mm, flaccid, base attenuate to slightly rounded, pseudopetiole absent, margins scabrous, apex acute to acuminate, glabrous to sparsely pilose on both sides, without tubercle-based hairs. Panicles 4–8 cm long, common axis 0.5–2 cm long. Racemes 3–5, digitate, ascending, straight, 4–8 cm long. Rachis fragile, flattened, margins ciliate, internodes linear, c. 1.5 mm long. Sessile spikelets , oblong to lanceolate, 2–2.5 mm long, callus setose. Lower glume oblong to lanceolate, chartaceous, midrib glabrous, dorsally flat or concave, smooth or scaberulous, rough at apex, glabrous, margins glabrous, apex obtuse, entire. Upper glume elliptic, back acute, glabrous, midrib glabrous, apex entire, acute, mucro c. 0.5 mm long. Lower florets absent. Upper lemma orbicular, c. 0.5 mm long, without veins, glabrous, apex incised to 0.2th of the lemma length, awn from a sinus, geniculate, column twisted, (incl. column) 6–8 mm long. Upper palea absent or minute. Anthers 3, c. 1 mm long. Pedicels linear, flattened, 1–1.5 mm long, margins pubescent. Pedicelled spikelets variously reduced.

Distribution — India (Assam), Burma (Pegu, Mandalay, Rangoon, Shan), Thailand (N: Nan; E: Nakhon Ratchasima), China (Guangdong, Yunnan).

Habitat — Forest margins, roadsides, c. 600 m altitude.

Figures

Map 3 Distribution of Microstegium delicatulum (Hook.f.) A.Camus.

Fig. 2 Microstegium delicatulum (Hook.f.) A.Camus. a. Habit; b. spikelets; c. lower glume; d. upper glume; e. upper lemma with long flexuous awn; f. joint of leaf sheath and leaf blade (all: Kurz 2738, K).