Dinebra

Dinebra* Fragm. Bot. Ill. 77 (1809).

Derivation:. From Arabic denab (queue), alluding to the long inflorescence.

Key references (keys and floras):. M.Lazarides, Tropical Grasses S.E. Asia 168–169 (1980); J.C.Tothill and J.B.Hacker, Grasses of Southern Queensland 200–201 (1983); B.K.Simon, Key to Australian Grasses 104 (1993); D.Sharp and B.K.Simon, AusGrass (2002); K.Mallet (ed.), Flora of Australia 44B: Poaceae 3: 320–322 (2005).

W.D.Clayton & S.A.Renvoize, Genera Graminum (1986), genus (352).

Naturalised. 3 species, from tropical Africa and Asia. 1 species in Australia, Qld.

Habit. Annual, tufted to decumbent. Leaf blades broad (rarely) or narrow. Ligule a fringed membrane (very narrow).

Inflorescence. Inflorescence of spicate main branches or paniculate (a raceme of numerous small spikes which become deflexed at maturity, the lower spikelets of each spike often replaced by small deciduous branchlets), a racemose panicle with spikelets all similar. Spikelet-bearing axes when disarticulating, falling entire (the smaller laterals deciduous).

Spikelets. Spikelets laterally compressed, 2 flowered to more than 2 flowered, with 1 fertile floret or with 2 or more fertile florets, solitary, sessile; with naked rachilla extension. Fertile spikelets cuneate, adaxial (with lower glume against rachis), disarticulating above glumes.

Glumes. Glumes more or less equal, exceeding florets, long relative to adjacent lemmas (much exceeding them), pointed, awned (acuminate-aristate), keeled (subulate), dissimilar or similar (leathery or membranous, the lower often very asymmetrical). Lower glume 1–2 nerved. Upper glume 1–2 nerved.

Florets. Fertile florets 2–3. Lemmas pointed to incised, less firm than glumes to similar in texture to glumes (thinly membranous), not becoming indurated, muticous to mucronate, 3 nerved, hairy (usually, pilose on the nerves) or glabrous, 1 keeled (slightly) or not keeled. Palea 2 nerved. Lodicules 2. Stamens 3. Grain small, ellipsoid, shallowly concave on the hilar side, trigonous. Hilum short. Embryo large, with one scutellum bundle.

Kranz Anatomy. C4.

2n = 20, 2 ploid, commonly adventive.

Habitat. Helophytic to mesophytic (in seasonally wet places). Savanna. Shade species, or species of open habitats.

Classification. Chloridoideae; Cynodonteae.

Notes. The genus is linked to Leptochloa (Clayton and Renvoize, 1986).

Types Species. D. arabica Jacq. = D. retroflexa (Vahl)Panz.

Biogeographic Element. Clifford & Simon 1981, Simon & Jacobs 1990: Naturalised.

AVH 2011

All species except L. fusca and L. digitata have been moved to Dinebra, but these changes are yet to reflected on AVH. L. fusca is now treated again in the genus Diplachne

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith