| # The grass genera of the world |

L. Watson, T.D. Macfarlane, and M.J. Dallwitz

### Hemisorghum C.E. Hubb.

Habit, vegetative morphology. Stout perennial; caespitose. Culms herbaceous. Culm internodes solid. Leaf blades linear-lanceolate; broad; flat. Ligule a fringed membrane (?).

Reproductive organization. Plants bisexual, all with bisexual spikelets; with hermaphrodite florets. The spikelets of sexually distinct forms on the same plant; hermaphrodite and sterile; overtly heteromorphic (the pedicelled smaller, lacking the L1); all in heterogamous combinations.

Inflorescence. Inflorescence paniculate (a large decompound panicle with whorled, triquetrous or angular, scabrid branches); open; espatheate; not comprising ‘partial inflorescences’ and foliar organs (?). Spikelet-bearing axes ‘racemes’ (few to several-noded); solitary; with very slender rachides; disarticulating; disarticulating at the joints. ‘Articles’ linear (slender); not appendaged; disarticulating transversely. Spikelets paired; consistently in ‘long-and-short’ combinations; in pedicellate/sessile combinations. Pedicels of the ‘pedicellate’ spikelets free of the rachis. The ‘shorter’ spikelets hermaphrodite. The ‘longer’ spikelets sterile.

Female-sterile spikelets. The sterile pedicelled spikelets without an L1.

Female-fertile spikelets. Spikelets compressed dorsiventrally (?); falling with the glumes (falling with the joint and the pedicelled spikelet). Rachilla terminated by a female-fertile floret. Hairy callus present (with a ring of minute hairs). Callus short; blunt.

Glumes two; more or less equal; long relative to the adjacent lemmas; G2 with ciliate margins; awnless; very dissimilar (leathery, the G1 obtuse, dorsally flat or slightly convex, 2-keeled for most of its length with the margins inflexed towards the base, the G2 lanceolate, acute, dorsally rounded, becoming 1-keeled upwards). Lower glume two-keeled; convex on the back to flattened on the back; not pitted; relatively smooth; 8–11 nerved. Upper glume 7 nerved. Spikelets with incomplete florets. The incomplete florets proximal to the female-fertile florets. The proximal incomplete florets 1; sterile. The proximal lemmas awnless; 2 nerved; more or less equalling the female-fertile lemmas to decidedly exceeding the female-fertile lemmas; similar in texture to the female-fertile lemmas (thinly membranous to hyaline); not becoming indurated.

Female-fertile florets 1. Lemmas less firm than the glumes (thin); not becoming indurated; incised; minutely 2 lobed; not deeply cleft (minutely bidentate); awnless, or mucronate (between the teeth); ciliolate; non-carinate; without a germination flap; 1 nerved. Palea present; relatively long (about as long as the lemma); linear oblong; awnless, without apical setae; textured like the lemma; not indurated; nerveless; keel-less. Lodicules present; 2; free; fleshy; glabrous. Stamens 3. Ovary apically glabrous. Styles fused (at base). Stigmas 2; red pigmented.

Fruit, embryo and seedling. Fruit compressed dorsiventrally (plano-convex). Hilum short. Embryo large.

Classification. Watson & Dallwitz (1994): Panicoideae; Andropogonodae; Andropogoneae; Andropogoninae. Soreng et al. (2015): Panicoideae; Andropogonodae; Andropogoneae; Sorghinae. 2 species.

Distribution, phytogeography, ecology. India, Burma, Southeast Asia.

On hillsides and riverbanks.

Special comments. Anatomical data wanting.

Illustrations. • Hemisorghum mekongense: Neamsuvan et al., Gard. Bull. Singapore 61, 151–157 (2009).

We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or the interactive key, which allows access to the character list, illustrations, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, distributions of character states within any set of taxa, geographical distribution, and classifications. See also Guidelines for using data taken from Web publications.

Cite this publication as: ‘Watson, L., Macfarlane, T.D., and Dallwitz, M.J. 1992 onwards. The 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. Version: 15th June 2025. delta-intkey.com’.

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