The grass genera of the world
~ Panicum Sect Lorea
Type species: R. trinii (Kunth) Zuloaga & Morrone.
Habit, vegetative morphology. Perennial; forming robust tussocks, rhizomatous and caespitose. Leaves mostly basal. Leaf blades pungent, linear to lanceolate; narrow; flat, or rolled. Ligule present, or absent; when present, a fringed membrane, or a fringe of hairs.
Reproductive organization. Plants bisexual, all with bisexual spikelets; with hermaphrodite florets. The spikelets hermaphrodite.
Inflorescence. Inflorescence a false spike, with spikelets on contracted axes, or paniculate; very contracted; spicate.
Female-fertile spikelets. Spikelets elliptic; abaxial; compressed laterally; biconvex; falling with the glumes. Rachilla terminated by a female-fertile floret.
Glumes two; very unequal; (the upper) about equalling the spikelets; long relative to the adjacent lemmas; hairy, or hairless (pilose or glabrous); awnless; somewhat carinate; similar. Lower glume 0.5–0.8 times the length of the upper glume; shorter than the lowest lemma; 3–5 nerved. Upper glume 5(–7) 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. Palea of the proximal incomplete florets reduced. The proximal incomplete florets male.
Female-fertile florets 1. Lemmas decidedly firmer than the glumes; shiny, smooth; becoming indurated; entire; awnless; hairless; glabrous; non-carinate; having the margins inrolled against the palea; 5(–7) nerved. Palea present; relatively long; awnless, without apical setae.
Fruit, embryo and seedling. Hilum short. Embryo large.
Transverse section of leaf blade, physiology. Supposedly C3; XyMS+. Mesophyll with non-radiate chlorenchyma.
Classification. Watson & Dallwitz (1994): not described separately. Soreng et al. (2015): Panicoideae; Panicodae; Paspaleae; Paspalinae. 10 species.
Distribution, phytogeography, ecology. Brazil.
References, etc. Morphological/taxonomic: Sede, S.M., Morrone, O., Giussani, L.M., and Zuloaga, F.O. (2008). Phylogenetic Studies in the Paniceae (Poaceae): a realignment of section Lorea of Panicum. Syst. Bot. 33(2):284–300.
Special comments. Anatomical data wanting.
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, distributions of character states within any set of taxa, geographical distribution, and classifications. See also Guidelines for using data taken from Web publications.
Cite this publication as: ‘Watson, L., Macfarlane, T.D., and Dallwitz, M.J. 1992 onwards. The 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. Version: 13th November 2017. delta-intkey.com/grass’.