Germainia capitata Balansa & Poitr. — Plate, 1873

Teerawatananon, A., Sungkaew, S., Boontia, V. & Hodkinson, T. R., 2013, A taxonomic revision of Germainia (Andropogoneae: Poaceae) in Thailand, Blumea 57 (3), pp. 221-228 : 224

1. Germainia capitata Balansa & Poitr. — Plate 1

Germainia capitata Balansa & Poitr.(1873) 344,f. 1–9. — Themeda capitata (Balansa & Poitr.) Roberty var. capitata Roberty (1960) 101, nom. inval. — Type: Germain s.n. in Herb. A. Poitrasson (holo L, barcode L 44451,photo in BRI; P), Vietnam, Ho Chi Minh (‘Cochinchine, Saigon’).

Germainia schmidiana A. Camus (1957) 186. — Type: Schmid 2349 (holo probably in Herb. M. Schmid, Paris, fide J.F. Veldkamp, pers. comm.), Vietnam, Khanh Hoa, Cam Lâm (Ba Ngoi).

Perennial, tufted. Culms 30– 60(–90) cm tall, erect; nodes glabrous to pubescent. Leaf­sheaths 5 –13 cm long, basal sheaths tomentose, densely covered with white to pale yellow hairs to glabrous, upper sheath shorter than internodes. Ligule a ciliate membrane, up to 1.5 mm long, with a dense row of hairs behind the ligule. Leaf­blades linear, 7– 40 by 0.5 –1 cm, tomentose to sparsely pubescent or glabrous on both surfaces, margins thick, tomentose to scabrous. Racemes 2, 2– 4 cm long, capitate to elongate, usually with one main axis rarely with two, very closely appressed, composed of 4 –14 sessile and pedicelled spikelets, basal homogamous 1–4 in number; peduncles 20– 30 cm long, hirsute below the inflorescences. Sessile spikelets yellowish green to green, oblong, 15– 23 by 2.5 –4.5 mm; lower glumes coriaceous, oblong, 13– 22 by 3 –4.5 mm, pubescent to glabrous, obliquely bifid to muticous, upper margin ciliate, 7– 9-nerved, sometimes outer two nerves anastomosing; upper glumes linear-lanceolate, 16 –23 by 3– 4 mm, upper part pubescent, acute, upper margin ciliate, 3-nerved; lower lemmas linear-lanceolate, 15– 20 mm long, acute and ciliate, 1(– 3)-nerved; lower paleas ovate-lanceolate, 13–19 mm long, pubescent on nerves, bifid, upper margin ciliate; upper lemmas linear-lanceolate, 15– 20 mm long, upper part pubescent, acute, upper margin ciliate; upper paleas lanceolate, 15–20 mm long, pubescent on nerves, acute, upper margin ciliate; stamens 2, anthers reddish purple, 9–12 mm long. Pedicelled spikelets lanceolate, 8 –11 by 1.2 –2.5 mm, caducous; pedicels 5–7 mm long, hirsute; spikelet callus linear, 3– 3.5 mm long, attached obliquely, hairy, hairs 0.5 – 2 mm long; lower glumes lanceolate to ovate-lanceolate, 8–11 by 1.5– 2.5 mm, pubescent, obtuse to muticous, upper margin ciliate, 3-nerved; upper glumes ovate-lanceolate, 7–9 by 1–1.8 mm, pubescent, obtuse to truncate, upper margin ciliate, 3(–5)-nerved; lower florets neuter or suppressed, lower lemmas linear, 6 –7 mm long, truncate, upper margin ciliate, nerves obscure; lower paleas absent; upper lemmas linear, 3– 4 mm long, awns 6 – 9(–11.5) cm long, columns 4 – 6 cm long; upper paleas oblong, 5 –7 mm long, truncate and dentate, upper margin ciliate; styles 2, stigmas reddish purple, c. 1.5 mm long. Caryopsis oblong, 3 –4 mm long.

Distribution — Thailand (NE: Loei; E: Chaiyaphum, Si Sa Ket; SE: Chanthaburi; PEN: Satun, Songkhla). This species also occurs in Vietnam to S China (Guangdong, Yunnan), Malesia: Aru Isl., New Guinea (Irian Jaya: Kebar, Baliem; Papua New Guinea: W Sepik, W Prov.), Australia (N Queensland).

Habitat & Ecology — Wet and open sandy and clayey soil areas in tropical grasslands, pine forests, 0 –1300 m.

Vernacular name — Ya Kamong, from Bunpheng 898 (BKF).

Specimens examined. Anonymous 32, 57; Brass 5727, 6555, 8637, 11722; Bunpheng 898; Buwalda 5299; BW 12512 (Versteegh); Clarkson 7753; Heyligers 1615; Kerr 8831, 9583, 13687; Kostermans & Soegeng 814; Lazarides 7468; Maxwell 76­548, 85­215; NGF 9370 (Womersley), 10429 (White & Gray), 38777­2 (Henty & Katik), 49579 (Henty); O’Connor & Niyomdham 15679; Pullen 7210; Raynal 16983; Sampson 838a, 838b, 1162, 14302; Sharpe & Dowling 2264; Sharpe & Elsol 2660; Smitinand 367, 1794, 3598, 5856, 7154; SØrensen et al.2369; Teerawatananon & Sungkaew 834, 888, 889, 898; Tem & Ploenchit 367; Van Balgooy & Mamesah 6267, 6381; Van Beusekom et al. 4265 (NOT 9265); Van Leeuwen & Van der Ree 16–23 May 1958.

Notes — Chai-Anan (1972) divided this species into two groups of high (1000– 2000 m) and low (5– 50 m) altitudes. Of the specimens examined in this study, only the specimens collected from the summit of Phu Kradueng (1000–1300 m) are assignable to the high altitude plants, while the specimens collected from the other places (0 –800 m) are assignable to the low altitude plants. We agree with Chai-Anan that the distinction between the two forms is insufficient for any taxonomic recognition as some characters are inconsistent, e.g. the shape of the apex of the lower glume of sessile spikelet is variable and ranges from obliquely bifid to muticous which can be found in both groups of plants, although most specimens from low altitude tend to have obliquely bifid apices, while the specimens from high altitude tend to have muticous ones. More material for further study is needed to clarify this situation.

This scenario also happens with other grasses. For example, the disjunct distribution crossing the Equator and the Wallace which occurs in Hemarthria . Hemarthria pratensis (Balansa) Clayton ( Van den Heuvel & Veldkamp 2000: 462) ranging from Thailand to Vietnam was described as H. subulata Reeder from the Western Province of Papua New Guinea. Other instances even more intriguing are the temperate species Trisetum bifidum (Thunb.) Ohwi var. bifidum from China, Korea, Japan and then above 2660 m in Papua New Guinea: the Star Mts and Mt Victoria. Approximately 39 subalpine species of Poa L. in New Guinea belong to the Eurasian Homalopoa Dumort. and Stenopoa Dumort. (J.F. Veldkamp, pers. comm.).

Figures

Plate 1 a, b. Germainia capitata Balansa & Poitr.a. Habit;b. inflorescence.— c, d. Germainia khasyana Hack. c. Habit; d. inflorescence (a, b: Teerawatananon & Sungkaew 834; c, d: Teerawatananon & Sungkaew 906). — Photos: all A. Teerawatananon.