19 February 2020

Gigantochloa serik BS-0078

Gigantochloa serik BS-0078

Thai name: Not recorded. Malay name: buluh serik.
Distribution: INDONESIA: Sumatra, Java, Bali, native, endemic.
Description: "… Rhizomes short; pachymorph.
Culms erect; 1000–1500 cm long; 20–60 mm diam.; woody. Culm-internodes terete; hollow; 25–45 cm long; mid-green; distally glabrous, or hispid (black hairs). Lateral branches dendroid. Culm-sheaths persistent; 15–17 cm long; hispid; with appressed hairs; with black hairs; auriculate; with obtuse auricles; with 1–2 mm high auricles; glabrous on shoulders. Culm-sheath ligule entire, or ciliolate. Culm-sheath blade lanceolate; narrower than sheath; reflexed; 2.5–13.5 cm long; 6–13 mm wide; pubescent (sparsely). Leaf-sheaths pubescent. Leaf-sheath oral hairs scanty, or lacking; 1–4 mm long. Leaf-sheath auricles falcate; 1–1.5 mm long; obtuse. Ligule an eciliate membrane. Collar with external ligule. Leaf-blade base with a brief petiole-like connection to sheath. Leaf-blades lanceolate; 15–27 cm long; 20–34 mm wide. Leaf-blade surface glabrous, or pilose; sparsely hairy; hairy abaxially …" — Kew GrassBase. 
Specimen: BS-0078 [S6] (living plants), received from the USA in 2012, origin is Indonesia.

Characters:
(1) Culms straight, slightly bending outwards. Culm-internodes with narrow greenish-yellow stripes on lower and mid-culm; thin-walled. Branches several, with 1 slightly dominant, 2 subdominant, and a few smaller ones, rebranching.
(2) Culm size: Culm at 1.8 m height and 2.5 cm in diameter is with wall thickness 2 mm. Culm diameter increasing with height, gradually increasing from base to lower mid-culm up to 14% (e.g. basal diameter 3.5 cm, diameter 4.0 cm on 8th internode at 2.0 m above ground), then remaining constant for several meters and gradually decreasing towards top. A culm diameter which increases with the culm height between base and lower mid-culm has also been observed in some other species (e.g. in genus Dendrocalamus, Gigantochloa, Melocalamus, Schizostachyum) under cultivation at Baan Sammi: BS-0006, BS-0208, BS-0494, BS-0550, BS-0602, BS-0724. The diameter difference can be seen with the naked eye, but are not that impressive as in BS-0550.