Decaryella A. Camus
Habit, vegetative morphology. Annual. Culms 10–30 cm high; herbaceous. Culm nodes glabrous. Leaves not basally aggregated; non-auriculate. Leaf blades narrow; flat, or rolled; without cross venation; a fringed membrane.
Reproductive organization. Plants bisexual, with bisexual spikelets; with hermaphrodite florets. The spikelets all alike in sexuality.
Inflorescence. Inflorescence a single raceme (loose, narrow, 4–12 cm long); espatheate; not comprising ‘partial inflorescences’ and foliar organs. Spikelet-bearing axes persistent. Spikelets solitary; not secund; long pedicellate; not in distinct ‘long-and-short’ combinations.
Female-fertile spikelets. Spikelets about 4.5 mm long; compressed dorsiventrally; falling with the glumes (and with the pedicels). Rachilla prolonged beyond the uppermost female-fertile floret, or terminated by a female-fertile floret (?); the rachilla extension when present, with incomplete florets, or naked. Hairy callus present (comprising the long, hairy pedicel). Callus long; pointed.
Glumes present; two; more or less equal; long relative to the adjacent lemmas; hairy; pointed; awned (both having a terminal, subulate awn 3–7 mm long); non-carinate (dorsally rounded); similar (thick, leathery, smooth). Lower glume 5 nerved. Upper glume 5 nerved. Spikelets with female-fertile florets only, or with incomplete florets. The incomplete florets distal to the female-fertile florets. The distal incomplete florets merely underdeveloped. Spikelets without proximal incomplete florets.
Female-fertile florets 1–2. Lemmas less firm than the glumes (very thin); not becoming indurated; entire; pointed, or blunt; awnless; hairless; glabrous; non-carinate; 1 nerved, or 3 nerved. Palea present; entire; awnless, without apical setae; 2-nerved; 2-keeled.
Fruit, embryo and seedling. Embryo large.
Abaxial leaf blade epidermis. Costal/intercostal zonation conspicuous. Papillae absent. Microhairs present; chloridoid-type. Stomata common. Subsidiaries dome-shaped and triangular. Intercostal short-cells common; in cork/silica-cell pairs. Prickles and macrohairs present. Costal short-cells conspicuously in long rows. Costal silica bodies ‘panicoid-type’; dumb-bell shaped.
Transverse section of leaf blade, physiology. Lamina mid-zone in transverse section open.
C4; XyMS+. Mesophyll with radiate chlorenchyma. Bulliforms present in discrete, regular adaxial groups; associated with colourless mesophyll cells to form deeply-penetrating fans. All the vascular bundles accompanied by sclerenchyma. Combined sclerenchyma girders present. Sclerenchyma all associated with vascular bundles.
Taxonomy. Chloridoideae; main chloridoid assemblage.
Distribution, ecology, phytogeography. 1 species; Madagascar. Species of open habitats. Dry bush.
Paleotropical. Madagascan.
Special comments. Spikelet description fairly inadequate. 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).