| # The grass genera of the world |

L. Watson, T.D. Macfarlane, and M.J. Dallwitz

### Canastra (Filg.) Morrone, Zuloaga, Davidse & Filg.

~ Arthropogon

Habit, vegetative morphology. Perennial; caespitose. Culms 40–80 cm high; herbaceous. Culm nodes glabrous. Leaf blades narrow; 2–7 mm wide; not pseudopetiolate. Ligule present; a fringed membrane; 2–3 mm long.

Reproductive organization. Plants bisexual, all with bisexual spikelets; with hermaphrodite florets. The spikelets hermaphrodite.

Inflorescence. Inflorescence paniculate; contracted; more or less ovoid to spicate (congesed, linear to oblong, 5–17 cm long); espatheate; not comprising ‘partial inflorescences’ and foliar organs. Spikelets solitary to paired; pedicellate.

Female-fertile spikelets. Spikelets 2–4 mm long; lanceolate; abaxial; compressed dorsiventrally; falling with the glumes; with conventional internode spacings (?). The upper floret not stipitate (?). Rachilla terminated by a female-fertile floret. Hairy callus absent (the callus glabrous).

Glumes two; very unequal; about equalling the spikelets; long relative to the adjacent lemmas (i.e., the upper); hairless; scabrous; long awned; non-carinate; similar (in size and nervation). Lower glume 0.5 times the length of the upper glume; 1 nerved, or 3 nerved (? - according to Clayton et al.). Upper glume herbaceous, 5 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 fully developed to reduced (?). The proximal incomplete florets male (according to Morrone et al). The proximal lemmas similar to the upper glume, oblong, blunt; awnless; 5 nerved; not becoming indurated (leathery).

Female-fertile florets 1. Lemmas linear; not becoming indurated; blunt; awnless; hairless (smooth, or with apical prickle hairs); non-carinate; having the margins lying flat on the palea; 3 nerved (according to Morrone et al.). Palea present; not indurated (hyaline); 2-nerved; keel-less. Lodicules present; 2; free; fleshy; not toothed. Stamens 3. Stigmas 2.

Fruit, embryo and seedling. Disseminule a caryopsis enclosed in but free of the lemma and palea. Pericarp fused.

Abaxial leaf blade epidermis. Costal/intercostal zonation conspicuous. Papillae absent. Microhairs present; elongated; clearly two-celled; panicoid-type. Stomata common. Subsidiaries triangular. Intercostal short-cells common. Macrohairs and prickles absent. Costal silica bodies ‘panicoid-type’; cross shaped and dumb-bell shaped.

Transverse section of leaf blade, physiology. C3. Mesophyll with non-radiate chlorenchyma; not Isachne-type; with fusoids. The fusoids an integral part of the PBS. Leaf blade ‘nodular’ in section to adaxially flat. Midrib not readily distinguishable; with one bundle only; without colourless mesophyll adaxially. The lamina symmetrical on either side of the midrib. Bulliforms present in discrete, regular adaxial groups; in simple fans; nowhere involved in bulliform-plus-colourless mesophyll arches. Combined sclerenchyma girders absent. Sclerenchyma all associated with vascular bundles. The lamina margins with fibres.

Classification. Watson & Dallwitz (1994): genus not recognised. Soreng et al. (2015): Panicoideae; Panicodae; Paspaleae; Arthropogoninae. 1 species (C. lanceolatus).

Distribution, phytogeography, ecology. Brazil.

References, etc. Morphological/taxonomic: Grassbase (2016), https://www.mobot.org/MOBOT/Research/davidse/canastra/. Leaf anatomical: Morrone, Zuloaga, Davidse & Filgueiras (2001).

Special comments. In view of major discepancies between the Clayton et al. and Morrone et al. spikelet descriptions, this complilation is unreliable. Anatomical data for ts only.

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: 15th June 2025. delta-intkey.com’.

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