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The grass genera of the world

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

Polliniopsis Hayata

~ Microstegium

Type species: P. somae Hayata.

Habit, vegetative morphology. Decumbent (culm bases creeping, with rooting nodes). Culms 30–40 cm high; herbaceous. Leaf blades lanceolate; narrow; to 5 mm wide; without cross venation. Ligule truncate.

Reproductive organization. Plants bisexual, all with bisexual spikelets; with hermaphrodite florets. The spikelets all alike in sexuality; homomorphic.

Inflorescence. Inflorescence of spicate main branches, or paniculate (?- ‘of paired racemes’); non-digitate; espatheate; not comprising ‘partial inflorescences’ and foliar organs. Spikelet-bearing axes ‘racemes’; paired (slender, recurved, about 8 cm long); persistent (?-rachis tough). ‘Articles’ linear. Spikelets paired; pedicellate; consistently in ‘long-and-short’ combinations; unequally pedicellate in each combination. Pedicels of the ‘pedicellate’ spikelets free of the rachis. The ‘shorter’ spikelets hermaphrodite. The ‘longer’ spikelets hermaphrodite.

Female-fertile spikelets. Spikelets 5 mm long; compressed dorsiventrally; falling with the glumes. Rachilla terminated by a female-fertile floret. Hairy callus present.

Glumes two; long relative to the adjacent lemmas; awned; very dissimilar (the G1 2-aristate with 1 mm aristules, the G2 acuminate into an 8 mm awn). Lower glume flattened on the back; not pitted; relatively smooth. 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 hyaline, linear, 2-toothed; awned (the awn long, geniculate, from the sinus); more or less equalling the female-fertile lemmas; similar in texture to the female-fertile lemmas.

Female-fertile florets 1. Lemmas linear, similar to the L1 in texture and form; less firm than the glumes (hyaline); incised; 2 lobed; not deeply cleft (bidentate); awned. Awns 1; median; from a sinus; geniculate; hairy; much longer than the body of the lemma (about 10 mm long). Lemmas hairless; non-carinate; without a germination flap. Palea present, or absent (?); if present, very reduced. Lodicules present; 2; free; fleshy; glabrous. Ovary apically glabrous (?). Stigmas 2.

Fruit, embryo and seedling. Hilum short.

Classification. Watson & Dallwitz (1994): Panicoideae; Andropogonodae; Andropogoneae; Andropogoninae. Soreng et al. (2015): Panicoideae; Andropogonodae; Andropogoneae; Saccharinae. 1 species (P. somae).

Distribution, phytogeography, ecology. Formosa.

References, etc. Morphological/taxonomic: Hayata 1918.

Special comments. Fruit data wanting. Anatomical data wanting. Illustrations. • P. somai, spikelet details: B. Hayata, Ic. Pl. formosanarum (1918)

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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: 11th December 2017.’.