Grass Genera of the World

L. Watson 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); without cross venation; ligule present; an unfringed membrane (laciniate); 3 mm long.

Reproductive organization. Plants bisexual, 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 glabrous. Styles free to their bases. Stigmas 2.

Taxonomy. Panicoideae; Andropogonodae; Andropogoneae; Andropogoninae (seemingly).

Distribution, ecology, phytogeography. 1 species; Bombay.

Paleotropical. Indomalesian. Indian.

References, etc. Morphological/taxonomic: Bor 1949.

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).

Index