Microstegium spectabile (Trin.) 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 : 178

12. Microstegium spectabile (Trin.) A.Camus — Fig. 10 ; Map 10

Microstegium spectabile (Trin.) A. Camus (1921) 200; Hosok. (1935) 310, isonym. — Pollinia spectabilis Trin.(1832) 305. — Eulalia spectabilis (Trin.) Kuntze (1891) 775. — [ Pogonatherum glabratum (Brongn.) Roberty subvar. spectabile (Trin.) Roberty (1960) 389, nom. inval.]. — Type: Mertens in Herb. Trinius 57.1 (LE, microfiche IDC BT-16/1).

Pollinia spectabilis Trin.var. ternatana Backer (1922) 113;reprint:37. — Lectotype: Beguin 73 (holo BO), designated here with aid from Mr.A.Sumadijaya (BO).

Microstegium spectabile (Trin.) A.Camus forma cryptochaetum Ohwi (1941) 550. — Type: Hatusima 11084 (holo FU).

Microstegium okamotoi Honda (1942) 16. — Type: Okamoto 1 (holo TI).

Microstegium gratum auct. non Hack.

Annuals, mat-forming. Culms rambling, robust, 100–170 cm long, rooting from the lower nodes. Nodes glabrous. Sheaths glabrous, outer margin glabrous or hairy, oral hairs absent or ciliate. Ligule a glabrous membrane, c. 1 mm long. Blades lanceolate, 10–18 cm by 10–20 mm, firm, base attenuate to slightly rounded, pseudopetiole absent, margins scabrous, apex acute to acuminate, glabrous. Panicles 7–14 cm long, common axis 1–2.5 cm long. Racemes 10–40, digitate, ascending, straight, 7–10 cm long. Rachis fragile, semiterete, margins ciliate, internodes linear, 2.7–3.3 mm long. Sessile spikelets without a short stalk, deciduous with the adjacent joint and pedicel, oblong to lanceolate, 2.5–4 mm long, callus pilose. Lower glume oblong to lanceolate, coriaceous, midrib ciliolate, dorsally longitudinally grooved, smooth, glabrous, margins glabrous, apex acute, entire. Upper glume elliptic, back acute, glabrous, midrib glabrous, apex entire, attenuate, muticous or mucro c. 1 mm long. Lower florets absent or present, paleate or barren and epaleate. Lower lemma absent to present, oblong, c. 0.5 mm long, muticous. Upper lemma linear, c. 1 mm long, without veins, glabrous, apex entire, awn apical, flexuous, column absent, 4–10 mm long. Upper palea absent or minute. Anthers 3, 1.5–2 mm long. Pedicels linear, flattened, 2–2.5 mm long, margins pubescent. Pedicelled spikelets subequal to the sessile ones.

Distribution — Burma (Northern part), China ( Hong Kong), Taiwan, Malesia: Sumatra, Borneo, Celebes (Tomohon), Philippines (Mindanao), Lesser Sunda Islands ( Flores), Moluccas (Halmahera, Ternate), New Guinea (widespread), Micronesia ( Solomon Islands).

Habitat — Young secondary rain forest, sandy flood banks, 350–2000 m alt.

Notes — In the forma cryptochaetum from Ponape the awn is absent.

Honda (1942: 16) described an endemic species M. okamotoi in Taiwan based on only one specimen which was collected in Kaohsiung County and its holotype is deposited in the herbarium TI. It is odd that after its publication, no other authors mentioned this name anymore ( Hsu 1975, 1978, 2000, Koyama 1987, Chen & Phillips 2006). After comparing the type specimen with the specimens deposited in the European herbaria mentioned above, we conclude that M. okamotoi is a synonym of M. spectabile ( Chen et al. 2011b) .

The line drawing of this species has been published previously ( Chen et al. 2011b).

Figures

Map 10 Distribution of Microstegium spectabile (Trin.) A.Camus.

Fig. 10 Microstegium spectabile (Trin.) A.Camus. a. Habit; b. spikelets; c. lower glume; d. upper glume; e. upper lemma with long flexuous awn; f. upper palea; g. joint of leaf sheath and leaf blade (all: Darbyshire 7953, L).