SUPPLEMENTARY STUDY ON SOME MORPHOLOGICAL CHARACTERISTICS OF Bambusa nghiana V.T. Tran IN VIETNAM

Abstract

Lùng (Bambusa nghiana V.T. Tran) is a pachymorph bamboo with short-necked rhizomes, curved into a sickle shape, 20 - 25 cm long, with 14 - 16 nodes covered by scale-like sheaths, and bearing 7 - 8 large dormant buds capable of forming shoots. Culms are erect, terete, smooth (unarmed), 8 - 10 cm (sometimes up to 12 cm) in diameter, and 15 - 17 m (sometimes up to 20 m) tall. The nodes are not prominent, without a ring of aerial roots. Culm sheath consists of sheath, blade, auricles, and ligule. The sheath is bell-shaped, 30.2 - 38.1 cm high, with a lower base 22.3 - 28.3 cm wide and an upper base 7 - 9 cm wide; inner surface glabrous, outer surface covered with stiff hairs. Culm-sheath blade is isosceles triangular, 9 - 15 cm long, 6 - 8 cm wide at the base, covered with stiff hairs on both surfaces. Auricles are thin, wrinkled, 2 - 3 cm long, 0.5 - 0.7 cm wide, with stiff bristles along the upper margin. Ligule is located inside the sheath at the junction with the blade, thin and narrow (< 0.1 cm), with a row of stiff bristles 0.9 - 1.1 cm long on the upper margin. Branching occurs from 1/2 to 2/3 of the culm height; each node has many small branches with a base diameter ≤ 0.9 cm, without a dominant primary branch. Leaf complements bear 11 - 13 leaves, arranged alternately in one plane. Inflorescences are clustered in groups of 13 - 23 pseudospikelets at the nodes of branches and culms. Pseudospikelets are lanceolate, 2.5 - 3.6 cm long, 0.9 - 1.2 cm wide. Each pseudospikelet contains 5 - 7 flowers, but only 3 - 4 are perfect flowers. Flowers are bisexual, arranged alternately and symmetrically along the main axis forming a flattened lanceolate shape; bracts (glumes) are obovate, 1.2 - 1.4 cm high. Lemma and palea are thin, enclosing the stamens and pistil. Ovary is ovoid; style 3-cleft, purple; stamens have 4 - 6 purple anthers, 0.4 - 0.5 cm long, with slender filaments hanging 1 - 1.5 cm long when extruded. Fruit is a caryopsis, ellipsoid, 1.1 - 1.4 cm long, 0.3 - 0.4 cm wide. Seed is rice-grain-like, ellipsoid, 1 - 1.3 cm long, 0.25 - 0.35 cm wide.