Gigantochloa multifloscula, Nguyen & Xia & Tran, 2012

Gigantochloa multifloscula View in CoL

H.N.Nguyen, N.Xia & V.T.Tran, sp. nov. ( Fig. 1 View FIG )

Species nova habitu ceteris Gigantochloae speciebus similis, sed ramis aequalis, flosculisque compositis, differt.

TYPUS. — Vietnam. Prov. Dong Nai, Cat Tien, Km 145 on the road Saigon to Dalat , fl. 25. I.1953, Schmid 1506 (holo-, P!).

PARATYPUS. — Vietnam. Prov. Dong Nai, Cat Tien, Km 140 on the road Saigon to Dalat , fl. 15.V. 2005, 150 m asl, H. N . Nguyen , V. T . Tran 52005460 (Herbarium of the Forest Science Institute of Vietnam – FSIV!) .

OTHER MATERIAL EXAMINED. — Vietnam. Cochinchina, Pro. Bien Hoa, Chua Chan Moutain , Pro. Bien Hoa , Cochinchine , IX.1865, Pierre 6665. — Cochinchine, Bara Mountain , fl. 23.VIII.1930, Poilane 17328 ( P) . — Km 155 on the road Saigon-Dalat, 200 m als, fl. 14. I.1954 , Schmid 1828. — Prov. Lam Dong, Da Teh District , Da Teh Lake , fl. VIII.2008, new shoots are developed between June-August, V.T. Tran 82008461 (FSIV). DISTRIBUTION HABITAT AND LOCAL USES. — Gigantochloa multifloscula sp. nov. was found in several populations. They grow in the degraded natural forest in valleys and mountain gorges, between 100 and 800 m asl, southern Vietnam. This species is of considerable importance to the local people. Its culms are used for making handicrafts and household tools. The shoots are edible .

ETYMOLOGY. — The specific epithet refers to the spikelet comprising 4-5 florets.

DESCRIPTION

Densely tufted with rhizomes short, pachymorphous. Culms erect, 4-8 m tall; internodes 20-30 cm long and 3-5 cm in diameter, when young densely covered with appressed white hairs, becoming rough by silicifying: culm walls 3-5 mm thick; nodes slightly swollen. Mid-culm branch complement with three subequal branches, and usually several smaller branchlets from its base. Culm sheaths early deciduous, when young greenish brown and densely covered with appressed black brown bristles on the abaxial side, then becoming yellow and glabrous, 13-15 × 9-11 cm, apex 3-4 cm wide, with dense purple brown marginal hairs; blade triangular, erected, when young densely covered with appressed black brown bristles on both sides, then glabrous, 8-10 × 2.5-3.5 cm: auriculate low rim c. 2 × 1 mm; ligule 1-2 mm long. Leaf blades oblongobovate, base broadly cuneate, 24-28 × 3-3.5 cm, veins 9-10 pairs, adaxial side densely covered by white cilia; leaf sheaths glabrous, one margin erect the second horizontal; ligulate low rim c. 2 mm long; petiole 4 × 3 mm. Pseudospikelets in clusters at the distal nodes, c. 10 mm long; 4-5 fertile florets, falling together, a sterile terminal floret and 2-3 sterile basal florets with lemma only; lemma ovate-orbicular, c. 8-9 mm wide, veins 18-20 pairs, apex obtuse with a mucro c. 0.5 mm long, densely covered by white cilia along the margins hyaline, and white bristles at the base of the abaxial side; palea 2-keeled, oblong-lanceolate 5-7 × 3-4 mm, veins inconspicuous, with dense white bristles along the margins and sparse white cilia on the abaxial side, apex bifid; lodicules absent; stamens 6, filaments joined in a tube c. 5-6 × 0.3 mm: style slender; stigma 1 plumose; ovary hairy. Fruit unknown.

REMARKS

This remarkable species is quite dissimilar to those already published for Gigantochloa , currently recognized by its mid-culm branch complement with no dominant branch, wall thin, florets falling together, lemma ovate-orbicular, 8-9 × 8-9 mm.