Chumsriella Bor
Named for Chumsri Chaianan, Thai agrostologist.
Sometimes referred to Germainia
Habit, vegetative morphology. Annual. Culms 10 cm high; herbaceous. Leaves not basally aggregated; non-auriculate. Leaf blades narrow; 2–3 mm wide (1–2 cm long); flat (hairy); without cross venation; persistent; ligule present; a fringe of hairs.
Reproductive organization. Plants monoecious with all the fertile spikelets unisexual; without hermaphrodite florets. The spikelets of sexually distinct forms on the same plant; female-only and male-only; overtly heteromorphic (the pedicellate, female spikelets hairy and long-awned, the sessile males hairless and awnless); all in heterogamous combinations.
Inflorescence. Inflorescence terminal, consisting of a pair of short ‘racemes’ on a long peduncle. Primary inflorescence branches 2. Inflorescence spatheate (subtended by a spathiform sheath with reduced lamina). Spikelet-bearing axes ‘racemes’ (3–4 noded only); the spikelet-bearing axes with 2–3 spikelet-bearing ‘articles’, or with 4–5 spikelet-bearing ‘articles’; spikelet-bearing axes paired (the pair fused by the lowest two joints); with substantial rachides (in proportion to their size); persistent. Spikelets paired (including the pair terminating the ‘raceme’); sessile and pedicellate; consistently in ‘long-and-short’ combinations; in pedicellate/sessile combinations. Pedicels of the ‘pedicellate’ spikelets free of the rachis. The ‘shorter’ spikelets male-only. The ‘longer’ spikelets female-only.
Female-sterile spikelets. The sessile male spikelets 3–4 mm long, with 1–2 awnless florets, the lower sterile, the upper with three stamens. Rachilla of male spikelets terminated by a male floret. The male spikelets with glumes; with proximal incomplete florets; usually 2 floreted. The lemmas awnless. Male florets 1; 3 staminate.
Female-fertile spikelets. Spikelets 2.5 mm long; falling with the glumes (deciduous from the cupular pedicel-tip). Rachilla terminated by a female-fertile floret.
Glumes two; more or less equal; long relative to the adjacent lemmas (exceeding them); hairy (densely brown-pilose); lanceolate, attenuate to more or less bifid apices; awnless; non-carinate; similar (but G2 narrower, less densely hairy). Lower glume not two-keeled; not pitted. Spikelets with female-fertile florets only (i.e., lacking the sterile andropogonoid L1); without proximal incomplete florets.
Female-fertile florets 1. Lemmas lanceolate, produced into the awn; less firm than the glumes (hyaline below, papery beneath the awn); not becoming indurated; entire; awned. Awns 1; median; apical; geniculate (bigeniculate); hairy; much longer than the body of the lemma (30 mm or more long); entered by one vein. Lemmas non-carinate; without a germination flap; 1 nerved. Palea present; conspicuous but relatively short (about 1 mm long - i.e., half lemma length); entire (oblong-acute); awnless, without apical setae; not indurated; keel-less. Stamens 0. Ovary glabrous. Styles fused (briefly). Stigmas 2.
Fruit, embryo and seedling. Fruit small. Hilum short. Embryo large (3/4 as long as the grain).
Taxonomy. Panicoideae; Andropogonodae; Andropogoneae; Andropogoninae.
Distribution, ecology, phytogeography. 1 species; Thailand.
Paleotropical. Indomalesian. Indo-Chinese.
References, etc. Morphological/taxonomic: Bor 1968b; Chaianan 1972.
Special comments. Anatomical data wanting.
Cite this publication as: Watson, L., and Dallwitz, M. J. (1992 onwards). ‘Grass Genera of the World: Descriptions, Illustrations, Identification, and Information Retrieval; including Synonyms, Morphology, Anatomy, Physiology, Phytochemistry, Cytology, Classification, Pathogens, World and Local Distribution, and References.’ http://biodiversity.uno.edu/delta/. Version: 18th August 1999. Dallwitz (1980), Dallwitz, Paine and Zurcher (1993 onwards, 1998), and Watson and Dallwitz (1994), and Watson, Dallwitz, and Johnston (1986) should also be cited (see References).