Microstegium brandisii (Hook.f.) Rhind

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

2. Microstegium brandisii (Hook.f.) Rhind — Fig. 1 ; Map 2

Microstegium brandisii (Hook.f.) Rhind (1945) 632. — Coelarthron brandisii

Hook.f. (1896a) 164; (1897) t. 2517. — Type: Brandis s.n. (holo K). Pollinia clavigera Backer (1922) 110 (reprint p. 34). — Microstegium clavigerum (Backer) Henrard (1940) 453. — Type: Backer 21177 (holo BO; L). Microstegium eucnemis auct. non A.Camus. Pollinia eucnemis auct. non Nees ex Steud.

Annuals, mat-forming. Culms rambling, slender, 25–40 cm long, rooting from the lower nodes. Nodes glabrous. Sheaths glabrous or puberulous, outer margin glabrous, oral hairs scanty or absent. Ligule a glabrous membrane, 0.5–0.75 mm long. Blades ovate to lanceolate, 1.5–8 cm by 6–15 mm, firm, margins smooth, apex acute, glabrous or sparsely pilose. Panicles 3–7 cm long. Racemes solitary, ascending, straight or arcuate. Rachis angular, margins villous, internodes pyriform, 3–4 mm long. Sessile spikelets oblong to lanceolate, 3–6 mm long, callus pilose or setose. Lower glume oblong to lanceolate, coriaceous, midrib glabrous, dorsally concave, scaberulous all over, glabrous, margins ciliate or setose, apex acute, entire or dentate. Upper glume elliptic, back acute, glabrous, midrib ciliate, apex acute, mucro 1–5 mm long. Lower florets absent to paleate, male. Lower lemma when present, oblong to lanceolate, c. 4 mm long. Upper lemma lanceolate, 1.5–2.25 mm long, without veins, apex entire or incised to 0.33–0.5th of the lemma length, awn apical or from a sinus, geniculate, column straight to twisted, 11–16 mm long. Upper palea elliptic, 1–2 mm long, 0.75th times as long as the lemma, membranous. Anthers 3, 1.5–2.5 mm long. Pedicels broadly clavate, V-shaped, 2.5–3 mm long, margins pubescent. Pedicelled spikelets variously reduced, male or neuter.

Distribution — Burma (provenance of type uncertain), Malesia: W to E Java (Padalarang to Madura), and Taiwan.

Habitat — Grassy road margins, near Tectona grandis (Teak) , on bare limestone, 50–700 m altitude.

Collector’s notes — Caespitose. Rachis fragile.

Notes — Microstegium brandisii is usually treated as a synonym of M. eucnemis . However, M. eucnemis has erect culms and its inflorescence has 3–5 digitate racemes. Microstegium brandisii has procumbent culms and its inflorescence is a solitary raceme. In our opinion, it is more appropriate to combine it with M. clavigerum .

This is another example of a disjunct distribution of drought plants between Burma and E Java. Curiously, it has been also found in Taiwan recently.

Figures

Map 2 Distribution of Microstegium brandisii (Hook.f.) Rhind.

Fig. 1 Microstegium brandisii (Hook.f.) Rhind.a. Habit; b. spikelets;c. lower glume; d. upper glume; e. lower lemma;f. upper lemma with awn; g. upper palea; h. joint of leaf sheath and leaf blade (all: Kurz 1217, K).