Boivinella A. Camus
Sometimes referred to Cyphochlaena
Habit, vegetative morphology. Culms 5060 cm high; herbaceous. Plants unarmed. Sheath margins free. Sheaths basally inflated. Leaf blades ovate to elliptic (and attenuate); broad; 1517 mm wide (and 89 cm long); cordate (or subcordate), or not cordate, not sagittate; not pseudopetiolate; without cross venation (or these not mentioned); membranous, long-pilose.
Reproductive organization. Plants bisexual, with bisexual spikelets; with hermaphrodite florets. The spikelets of sexually distinct forms on the same plant; hermaphrodite and sterile; overtly heteromorphic.
Inflorescence. Inflorescence of spicate main branches (of dorsiventral false spikes at the apex of the culm); non-digitate; espatheate; not comprising partial inflorescences and foliar organs. Spikelet-bearing axes racemes; solitary; with substantial rachides; persistent. Spikelets paired (seemingly); secund (the rachis dorsiventral); biseriate (the pairs in two rows); sessile and pedicellate (the hermaphrodite spikelets short-pedicelled); consistently in long-and-short combinations; in pedicellate/sessile combinations. Pedicels of the pedicellate spikelets free of the rachis. The shorter spikelets sterile (reduced to a glume). The longer spikelets hermaphrodite.
Female-sterile spikelets. The sterile spikelets sessile, reduced to one dorsally compressed glume.
Female-fertile spikelets. Spikelets unconventional (because of the extra glume, representing the sessile spikelet); 2.22.5 mm long; abaxial; strongly compressed laterally; falling with the glumes. Rachilla terminated by a female-fertile floret.
Glumes two; more or less equal; about equalling the spikelets, or exceeding the spikelets; long relative to the adjacent lemmas; dorsiventral to the rachis; hairless; without conspicuous tufts or rows of hairs; awned to awnless; very dissimilar (G1 subulate, and subaristate, G2 obtuse and muticate). Lower glume relatively smooth; 1 nerved. Upper glume 3 nerved. Spikelets with incomplete florets. The incomplete florets proximal to the female-fertile florets. Spikelets with proximal incomplete florets. The proximal incomplete florets 1; paleate; male. The proximal lemmas saccate; awnless; decidedly exceeding the female-fertile lemmas; decidedly firmer than the female-fertile lemmas (cartilaginous, umbonate).
Female-fertile florets 1. Lemmas less firm than the glumes; not becoming indurated; white in fruit (whitish); awnless, or mucronate (?); hairless; apically subgibbous; having the margins lying flat on the palea. Palea present; not indurated (thin). Stamens 6. Ovary glabrous. Stigmas 2.
Fruit, embryo and seedling. Fruit small (1.5 mm long); compressed laterally (and subtriangular).
Abaxial leaf blade epidermis. Costal/intercostal zonation conspicuous. Mid-intercostal long-cells rectangular; having markedly sinuous walls. Microhairs present; panicoid-type. Stomata common. Intercostal short-cells common. Costal short-cells conspicuously in long rows. Costal silica bodies panicoid-type.
Transverse section of leaf blade, physiology. C3; XyMS+. Mesophyll with radiate chlorenchyma. Bulliforms present in discrete, regular adaxial groups; in simple fans. All the vascular bundles accompanied by sclerenchyma. Sclerenchyma all associated with vascular bundles.
Taxonomy. Panicoideae; Panicodae; Paniceae (Boivinelleae).
Distribution, ecology, phytogeography. 2 species; Madagascar.
Paleotropical. Madagascan.
References, etc. Morphological/taxonomic: Camus 1925b; Bosser 1965.
Special comments. Fruit 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).