Microstegium dispar (Nees) 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 : 167

4. Microstegium dispar (Nees) A.Camus — Fig. 3 ; Map 4

Microstegium dispar (Nees) A. Camus (1921) 200. — Pollinia dispar Nees ex Steud. (1854b) 410. — Eulalia dispar (Nees ex Steud.) Kuntze (1891) 775. — Type: Junghuhn s.n. (holo B, lost?; not found in L, U), Java, prope Mt Sumbing. — Neotype: Docters van Leeuwen­Reijnvaan 8968 (holo L; BO), designated here.

Pollinia geminata Merr. (1918) 16. — Type: Koorders 40873 (holo BO; K, L).

Annuals, mat-forming. Culms prostrate, of moderate stature, 60–150 cm long, rooting from the lower nodes. Nodes pubescent. Sheaths glabrous or pilose, outer margin glabrous, oral hairs absent, or bearded. Ligule a ciliolate membrane, 0.2–0.5 mm long. Blades lanceolate to linear, 2–12 cm by 3–10 mm, firm, base attenuate, margins scabrous, apex acute or acuminate, below glabrous to sparsely to densely pilose with tubercle-based hairs. Panicles 3.5–7 cm long, common axis c. 0.5 cm long. Racemes 2–5, digitate, ascending to patent, straight, 2–6 cm long. Rachis semiterete, margins ciliate, internodes linear, 3.25–4.75 mm long. Sessile spikelets lanceolate, 4–6 mm long, callus setose. Lower glume lanceolate, coriaceous, midrib glabrous, dorsally flat or concave, smooth, pilose at base, margins setose, apex acute, entire. Upper glume elliptic, back acute, pilose near the base, midrib glabrous, apex acute, muticous. Lower florets well-developed, paleate or epaleate. Lower lemma oblong, 3.5–4.5 mm long. Upper lemma lanceolate, 2.5–3.5 mm long, without veins, apex incised to 0.5–0.75th of the lemma length, awn from a sinus, geniculate, column straight or slightly twisted, 10–17 mm long. Upper palea absent or minute. Anthers 3, 2.5–3 mm long. Pedicels linear, semiterete, 2.5–3 mm long, margins pubescent. Pedicelled spikelets variously reduced.

Distribution — Malesia: Java (Priangan to Besuki: Arjuno, Hyang, Ijen, Ipis, Kawi, Kelut, Lawu, Merbabu, Papandajan, Sindoro, Sumbing), Lesser Sunda Islands ((Bali (Abang, Agung), Lombok (Rinjani)).

Habitat — Locally abundant in sunny open areas, grass jungles, Casuarina forest, colouring the vegetation pink (Van Steenis 4554, BO), 1500–2800 m altitude .

Collector’s notes — Culms erectopatent, or, on slopes, patent to hanging, red. Blades obliquely deflexed, red suffused.

Note — Distribution disjunct.

Figures

Map 4 Distribution of Microstegium dispar (Nees) A.Camus.

Fig. 3 Microstegium dispar (Nees) A.Camus. a. Habit; b. spikelets (front view); c. spikelets (rear view); d. lower glume; e. upper glume; f. lower lemma; g. upper lemma with awn; h. joint of leaf sheath and leaf blade (all: van Steenis 4299, K).