Pseudosorghum A. Camus
Habit, vegetative morphology. Erect or decumbent annual. Culms 40–100 cm high; herbaceous; branched above, or unbranched above. Culm internodes solid. Leaves not basally aggregated; non-auriculate. Leaf blades linear; narrow; 5–10 mm wide; without cross venation.
Reproductive organization. Plants bisexual, with bisexual spikelets; with hermaphrodite florets. The spikelets of sexually distinct forms on the same plant (heterogamous); hermaphrodite and sterile, or hermaphrodite and sterile; overtly heteromorphic; in both homogamous and heterogamous combinations (the lowest pair of some or all racemes sterile).
Inflorescence. Inflorescence paniculate (all-sidedly branched, of few-to-many simple or branched spikelike racemes); contracted (relatively dense); espatheate; not comprising ‘partial inflorescences’ and foliar organs. Spikelet-bearing axes ‘racemes’ (spiciform, peduncled); the spikelet-bearing axes with 4–5 spikelet-bearing ‘articles’ to with more than 10 spikelet-bearing ‘articles’ (few-to-many-jointed - the racemes fairly long, by contrast with Sorghum); spikelet-bearing axes with very slender rachides; disarticulating; disarticulating at the joints. ‘Articles’ linear; not appendaged; disarticulating transversely; densely long-hairy to somewhat hairy. Spikelets in triplets (a terminal triad), or paired (the rest); secund (all the pedicelled spikelets one one side); 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 hermaphrodite (except in lowest pair, where they may be male or sterile). The ‘longer’ spikelets male-only, or sterile.
Female-sterile spikelets. The basal barren spikelets lacking a palea.
Female-fertile spikelets. Spikelets 4–5.25 mm long; compressed dorsiventrally; falling with the glumes (with adjacent joint and pedicel). Rachilla terminated by a female-fertile floret. Hairy callus present (minute). Callus short; blunt.
Glumes two; more or less equal; long relative to the adjacent lemmas; glumes smooth, hairy or not; awnless; carinate (G2), or non-carinate (G1); very dissimilar (papery, the G1 truncate and 2-keeled, the G2 cymbiform and acute). Lower glume two-keeled; not pitted; relatively smooth; 9–13 nerved. Upper glume 7 nerved. Spikelets with incomplete florets. The incomplete florets proximal to the female-fertile florets. Spikelets with proximal incomplete florets. The proximal incomplete florets 1; epaleate; sterile. The proximal lemmas awnless; 2 nerved; similar in texture to the female-fertile lemmas (thinly membranous); not becoming indurated.
Female-fertile florets 1. Lemmas less firm than the glumes; incised; 2 lobed; deeply cleft (to about halfway); awned. Awns 1; median; from a sinus; geniculate; hairless (ciliolate along margins); much longer than the body of the lemma. Lemmas hairy (long-ciliate); non-carinate; without a germination flap. Palea present (but absent in the barren basal spikelet); relatively long; awnless, without apical setae; not indurated. Lodicules present; 2; free; fleshy; glabrous. Stamens 3. Ovary glabrous; without a conspicuous apical appendage. Styles free to their bases. Stigmas 2.
Cytology. 2n = 20.
Taxonomy. Panicoideae; Andropogonodae; Andropogoneae; Andropogoninae.
Distribution, ecology, phytogeography. 2 species; Indo-Malaysian. Mesophytic; shade species and species of open habitats.
Paleotropical. Indomalesian. Indian, Indo-Chinese, and Malesian.
References, etc. Morphological/taxonomic: Camus 1920.
Special comments. Fruit data wanting. 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).