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The grass genera of the world

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

Pogonachne Bor

From the Greek pogon (beard) and achne (chaff, scale), alluding to the hair-tufted upper glume.

Habit, vegetative morphology. Stilt-rooted annual. Culms 100 cm high; herbaceous. Leaf blades absent from the upper culm leaves; lower on the culms, broad; 8–15 mm wide (to 25 cm long); not pseudopetiolate; without cross venation. Ligule present; an unfringed membrane (laciniate); 3 mm long.

Reproductive organization. Plants bisexual, all with bisexual spikelets; with hermaphrodite florets. The spikelets of sexually distinct forms on the same plant; hermaphrodite and sterile (hermaphrodite and ‘reduced’ - but the latter are somewhat theoretical); overtly heteromorphic (though the vestigial, sessile spikelets are hardly recognisable as such).

Inflorescence. Inflorescence falsely paniculate (scanty, of single racemes and their spatheoles); spatheate; not comprising ‘partial inflorescences’ and foliar organs. Spikelet-bearing axes ‘racemes’; solitary; eventually disarticulating; tardily disarticulating at the joints (after the spikelets have fallen). ‘Articles’ linear; not appendaged. Spikelets paired (accepting the vestiges as spikelets); pedicellate, or sessile and pedicellate (accepting the vestiges, which are sometimes totally suppressed, as ‘sessile spikelets’); consistently in ‘long-and-short’ combinations (in vestigial form). Pedicels of the ‘pedicellate’ spikelets free of the rachis. The ‘shorter’ spikelets sterile (the ‘sessile spikelets’, when present, being reduced to small scales between internode and pedicel). The ‘longer’ spikelets hermaphrodite.

Female-sterile spikelets. The ‘sessile spikelets’ vestigial and reduced to small scales between the internode and the pedicel, or completely suppressed.

Female-fertile spikelets. Spikelets 7–10 mm long; strongly compressed laterally; falling with the glumes. Rachilla terminated by a female-fertile floret. Hairy callus present (the hairs down one side).

Glumes two; more or less equal; long relative to the adjacent lemmas; hairy; (the upper) with distinct hair tufts (with a tuft of hairs in the middle third); awnless; non-carinate (rounded on the back); very dissimilar (G1 ovate-lanceolate, entire and sparsely hairy towards the tip, G2 asymmetric, with a tuft of hairs above the middle). Lower glume not two-keeled (and wingless); convex on the back; not pitted; G1 several-nerved. Upper glume 5 nerved. Spikelets with incomplete florets. The incomplete florets proximal to the female-fertile florets. Spikelets with proximal incomplete florets. The proximal incomplete florets 1; sterile. The proximal lemmas awnless; 3 nerved; more or less equalling the female-fertile lemmas; similar in texture to the female-fertile lemmas (hyaline); not becoming indurated.

Female-fertile florets 1. Lemmas less firm than the glumes; incised; not deeply cleft; awned. Awns 1; median; from a sinus; geniculate; hairless (scabrid); much longer than the body of the lemma. Lemmas hairless; glabrous; non-carinate; without a germination flap; 1 nerved. Palea present; relatively long; entire; awnless, without apical setae; not indurated; 2-nerved; keel-less. Lodicules present; 2; free; fleshy; glabrous. Stamens 3. Anthers not penicillate; without an apically prolonged connective. Ovary apically glabrous. Styles free to their bases. Stigmas 2.

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

Distribution, phytogeography, ecology. Bombay.

References, etc. Morphological/taxonomic: Bor, 1949.

Special comments. Fruit data wanting. Anatomical data wanting.

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: 11th December 2017.’.