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DELTA sample data

M. J. Dallwitz and L. Watson

Panicum L.

Including Chasea Nieuw., Coleataenia Griseb., Dileucaden (Raf.) Steud., Eatonia Raf., Eriolytrum Kunth, Milium Adans., Monachne P. Beauv., Phanopyrum (Raf.) Nash, Polyneura Peter, Psilochloa Launert, Setiacis S.L. Chen and Y.X. Jin (? – original description inadequate)

Habit, vegetative morphology. Annual, or perennial (but no overwintering rosette – by contrast with Dichanthelium). Culms 20–400 cm high; woody and persistent, or herbaceous; branched above, or unbranched above. Culm nodes hairy, or glabrous. Leaf blades pseudopetiolate (rarely), or not pseudopetiolate. Ligule an unfringed membrane, or a fringed membrane to a fringe of hairs.

Inflorescence. Plants bisexual, with bisexual spikelets. Inflorescence paniculate (except in the Stolonifera group, where it consists of racemes and the distinction from Brachiaria breaks down); open, or contracted; not comprising ‘partial inflorescences’ and foliar organs. Spikelet-bearing axes persistent. Spikelets not secund (except the American Agrostoidea group, ‘Psilochloa’, etc.).

Female-fertile spikelets, florets, fruit. Spikelets 1.4–6 mm long; compressed dorsiventrally (with very few exceptions: e.g. P. hemitomum); falling with the glumes, or not disarticulating. Rachilla terminated by a female-fertile floret (very rarely prolonged, e.g. occasionally in P. heliophilum: Zuloaga and Morone 1991). Hairy callus absent. Glumes two; nearly always very unequal; (the longer) long relative to the adjacent lemmas; nearly always awnless (the G2 truncate to pointed, very rarely shortly awn-tipped). Upper glume 3–9 nerved. Spikelets nearly always with incomplete florets. The incomplete florets proximal to the female-fertile florets. The proximal incomplete florets 1, or 2 (rarely); male, or sterile. The proximal lemmas awnless. Female-fertile florets 1. Lemmas entire; pointed, or blunt; awnless (rarely minutely apiculate); non-carinate; with a clear germination flap; 3–11 nerved. Palea present; relatively long. Lodicules present; fleshy; glabrous. Stamens 3. Ovary glabrous. Stigmas 2; red pigmented. Fruit small. Hilum short (linear in (e.g.) P. glutinosum, P. macranthum, P. pilgerianum = Psilochloa).

Photosynthetic pathway, leaf blade anatomy. C4, or C3; biochemical type PCK (5 species), or NAD–ME (14 species), or NADP–ME (4 species); when biochemically tested, XyMS+ (C3, or C4 NAD-ME or PCK), or XyMS– (NADP-ME). Midrib conspicuous, or not readily distinguishable; with one bundle only, or having a conventional arc of bundles; with colourless tissue adaxially, or without colourless tissue adaxially. Many of the smallest vascular bundles unaccompanied by sclerenchyma, or all the vascular bundles accompanied by sclerenchyma (rarely).

Taxonomy, distribution. Panicoideae; Panicodae; Paniceae. About 370 species. Holarctic, Paleotropical, Neotropical, Australian, and Antarctic.

Anatomical references. Mainly Metcalfe 1960 and this project.

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, and distributions of character states within any set of taxa. See also Guidelines for using data taken from Web publications.

Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 1998 onwards. DELTA sample data: descriptions, illustrations, identification, and information retrieval. Version: 19th October 2016.’.