Annamocalamus kontumensis H. N. Nguyen, N.-H. Xia & V. T. Tran

Tran, Van Tien, Nguyen, Hoang Nghia & Xia, Nian-He, 2013, Annamocalamus H. N. Nguyen, N. - H. Xia & V. T. Tran, a new genus of bamboo (Poaceae) from Vietnam, Candollea 68 (1), pp. 159-165 : 161

Annamocalamus kontumensis H. N. Nguyen, N.-H. Xia & V. T. Tran , spec. nova ( Fig. 1 , 2 ).

Typus: Vietnam, Kon Tum Province: Ngoc Linh Mountain, Ngoc Linh village , c. 1200 m, 23.II.1995, fl. & fr., Averyanov & al. VH020 (holo-: P [ P00451097 ]).

Rhizomatis sympodialibus, rhizomemate brevi collo, culmi erectus, vaginis auriculis conspicuis, dorso dense adpresseque atro-strigosis, laminis triangularis, erectus, basis producens, deciduus, inflorrescentilis iterauctantilus, pseudospiculae ad convivia in foliis nodorum distal ramis florentibus, glumis 3, flosculis hermaphroditus 1, lodicula 3, stylus longis, stigmatibus 3, brevis, frutus carnosus.

Densely tufted with rhizomes short necked, pachymorph. Culms erect, 4-8 m tall; internodes 60-80 cm long and 3- 4.5 cm in diameter, when young densely covered with appressed white hairs, becoming rough when old due to silica; culms walls 2-3 mm thick; nodes slight swollen. Branches a cluster of slender subequal branches, none dominant, these branching further. Culm sheaths persistent, greenish brown, rough, when young covered with densely appressed purplebrown bristle on the abaxial surface; 20-25 cm long and 12- 16 cm wide at the base; apex 8-10 cm wide, margins dense purple-brown hairs; blade tardily deciduous, triangular, erected, base black-brown when young and produced upwards into rounded, 10-15 × 6-8 cm, abaxial dense white powder, margins dense cilia, adaxilly dense hairs at the base; one auricle standing, 2-2.5 × 0.4-0.6 cm, other one margin curved downwards, 1.5-2 × 0.4-0.5 cm, adaxilly dense purple-brown bristle, ca. 0.9 cm long; ligule ca. 0.3 cm long with dense paleciliate, ca. 0.3 cm long. Leaf blades oblong-obovate, base broadly cuneate, 30-34 × 3.5-4 cm, veins in 13-14 pairs, margins and adaxilly surface dense white cilia; leaf sheaths dense white cilia, auricles ca. 0.3 ×c a. 0.2 cm with slender bristles, 5-8 mm long; ligule low rim, ca. 1mm; petiole 4-5 × 2-3 mm. Pseudospikelets in groups at the distal nodes on leafless flowering branches, ca. 8 mm long; 1 fertile floret, glumes 3, upper most obovate, 4-5 × 2-3 mm, apex acute, mucronate, mucro ca. 1 mm long, veins in 5, margins short white-hispid, abaxial surface sparse white cilia; lemma oblong-lanceolate, 5-6 × 3-4 mm, veins in 9-11, apex acute, mucronate, mucro 1.5- 2 mm long, convolute and covering most of the palea, margins dense white cilia; palea oblong-lanceolate, 7-8 × 2.5-3 mm, veins in 9-11, strongly involutes, sparse white cilia, apex bifid ca. 1 mm long, with a narrow groove on the back (at the base rachilla is joined); lodicules 3, obovate-shaped, 0.7-1 × ca. 0.5 mm margins long cilia; stamens 6, filaments free, 4-5 × 0.4-0.5 mm; style long; stigmas 3, plumose; ovary glabrous, short stalked. Pericarp thick, apple shaped, fleshy, globose, top horizontal or slightly truncated in the middle, 12-15 × 12- 15 mm.

Distribution and habitat. – The new species grows in the degraded natural forest in valleys and mountain gorges, but is common along river or valleys, between 500 to 1200 m in the western highland of Vietnam.

Phenology. – Annamocalamus kontumensis flowered in December 1946 (Poilane 35696) and January 1995 (Averyanov & al.VH020). New shoots seems to develop between June to August.

Local uses. – This species is of considerable importance to the local people. Its culms are used for making handicrafts, household tools.

Etymology. – The specific epithet refers to the type locality, Kon Tum Province, Vietnam.

Paratypi. – VIETNAM. Kon Tum Province: Dak To District, Lo Xo Pass , 15°13’338’’N 107°44’052’’E, 1071 m, 28.VIII.2005, st., H. N. Nguyen, V. T. Tran 2820050540 ( FSIV); Dak To and Dak Blan District , 1.IX.1946, fl. & fr., Poilane 35696 ( P).

Figures

Fig. 1. – Holotype of Annamocalamus kontumensis H. N. Nguyen, N.-H. Xia & V. T. Tran. [Averyanov & al. VH020, P] [© Muséum National d’Histoire Naturelle. Reproduced with permission]

Fig. 2. – Annamocalamus kontumensis H. N. Nguyen, N.-H. Xia & V. T. Tran. A. Culm sheath; B. Section of culm sheath with auricles; C. Dorsal view of blade; D. Leafy branch; E. Section of leafy branch; F. Section of flowering branch; G. Spikelet; H. Dorsal view of lemma; I. Dorsal view of palea; J. Lodicules; K. Fleshy fruit. [A, F-K: Averyanov & al. VH020, P; B-E: Nguyen & Tran 2820050540, FSIV] [Drawing: Van Tien Tran]