Thyrsostachys Gamble

nonem

Habit

Perennial. Rhizomes short; pachymorph. Culms erect; 700-1500-2500 cm long; woody. Culm-internodes terete. Lateral branches dendroid. Branch complement many; in a horizontal line; with 1 branch dominant; thinner than stem. Culm-sheaths persistent; without auricles. Culm-sheath blade linear (1), or triangular (1). Ligule an eciliate membrane (1), or a ciliolate membrane (1). Leaf-blade base with a brief petiole-like connection to sheath. Leaf-blades deciduous at the ligule; lanceolate.

Inflorescences

Synflorescence bractiferous; linear (1), or fasciculate (1); with spathaceous subtending bracts; with axillary buds at base of spikelet. Fertile spikelets sessile.

Spikelets

Spikelets comprising 2 fertile florets, or 3 fertile florets (1); with a barren rhachilla extension. Spikelets lanceolate (1), or ovate (1); laterally compressed; 12-17.87-25 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes glabrous (1), or pubescent (1).

Fertile

Spikelets comprising 2 fertile florets, or 3 fertile florets (1); with a barren rhachilla extension. Spikelets lanceolate (1), or ovate (1); laterally compressed; 12-17.87-25 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes glabrous (1), or pubescent (1).

Glume

Glumes persistent; shorter than spikelet. Lower glume oblong (1), or ovate (1); 0.7-0.825-1 length of upper glume; membranous; without keels; 9 -veined (1), or 11-13 -veined (1). Lower glume surface pubescent. Lower glume apex acute. Upper glume oblong (1), or ovate (1); 0.5-0.8125-1 length of adjacent fertile lemma; membranous; without keels; 9 -veined (1), or 12-13 -veined (1). Upper glume lateral veins with cross-veins (1/1). Upper glume surface pubescent. Upper glume apex acute.

Florets

Fertile lemma oblong; membranous; without keel; 9-12 -veined (1), or 13 -veined, or 14-19 -veined (1). Lemma surface pubescent. Lemma apex acute. Palea 1 length of lemma; membranous (1), or chartaceous (1); 3-5 -veined (1), or 7-9 -veined (1); 2-keeled but the uppermost without keels (1), or 2-keeled (1). Palea keels ciliate. Palea surface glabrous (1), or pubescent (1). Palea apex dentate, or lobed.

Flowers

Lodicules absent (1), or 2 (1); ciliate (1/1); acute (1/1). Anthers 6. Stigmas 1 (1), or 3 (1). Ovary umbonate; glabrous.

Fruits

Caryopsis with adherent pericarp.

Distribution

Temperate Asia, or Tropical Asia.