DELTA home

The grass genera of the world

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

Chamaeraphis R.Br.

Type species: Type: C. hordeacea R.Br.

Including Setosa Ewart

Habit, vegetative morphology. Perennial; caespitose. Culms 20–50 cm high; herbaceous. Culm nodes glabrous. Culm internodes solid. Leaves mostly basal, or not basally aggregated; non-auriculate. Leaf blades narrow; not pseudopetiolate; without cross venation; persistent. Ligule an unfringed membrane.

Reproductive organization. Plants bisexual, all with bisexual spikelets; with hermaphrodite florets (rarely), or without hermaphrodite florets (usually with L1 male, L2 female).

Inflorescence. Inflorescence a false spike, with spikelets on contracted axes (densely spikelike, with distichously arranged, much reduced ‘racemes’); contracted. Primary inflorescence branches borne distichously. Inflorescence axes not ending in spikelets. Inflorescence espatheate; not comprising ‘partial inflorescences’ and foliar organs. Spikelet-bearing axes very much reduced (to a single spikelet, a pungent callus, and a stout bristle); disarticulating; falling entire (by contrast with Pseudoraphis, the reduced panicle branches disarticulate from the persistent main axis, complete with the pungent, bearded base, one spikelet and the awn-like tip). Spikelets subtended by solitary ‘bristles’ (the terminal branch ‘awns’ being so interpreted). The ‘bristles’ deciduous with the spikelets. Spikelets solitary; not secund; pedicellate.

Female-fertile spikelets. Spikelets oblong, or elliptic, or lanceolate, or ovate, or obovate; abaxial; compressed dorsiventrally; falling with the glumes (and with the branchlet). Rachilla terminated by a female-fertile floret. Hairy callus present.

Glumes two; very unequal; long relative to the adjacent lemmas; dorsiventral to the rachis (lower abax.); awnless. Lower glume shorter than the lowest lemma; much shorter than half length of lowest lemma; 0 nerved. Upper glume 9–11 nerved. Spikelets with incomplete florets. The incomplete florets proximal to the female-fertile florets. The proximal incomplete florets 1; paleate. Palea of the proximal incomplete florets fully developed. The proximal incomplete florets male. The proximal lemmas awnless.

Female-fertile florets 1. Lemmas decidedly firmer than the glumes; smooth; white in fruit; awnless, or mucronate (?); without a germination flap; 7–9 nerved. Palea present; 2-nerved. Lodicules present; 2; free; fleshy; glabrous. Stamens 0, or 3. Anthers not penicillate. Ovary apically glabrous. Styles fused. Stigmas 2.

Fruit, embryo and seedling. Fruit small; compressed dorsiventrally. Hilum short. Embryo large; waisted.

Abaxial leaf blade epidermis. Costal/intercostal zonation conspicuous. Papillae present; intercostal. Intercostal papillae not over-arching the stomata; consisting of one symmetrical projection per cell. Long-cells markedly different in shape costally and intercostally; of similar wall thickness costally and intercostally (thick walled). Intercostal zones exhibiting many atypical long-cells. Mid-intercostal long-cells rectangular; having markedly sinuous walls. Microhairs present; panicoid-type. Stomata common. Subsidiaries non-papillate. Guard-cells overlapping to flush with the interstomatals. Intercostal short-cells common; in cork/silica-cell pairs; silicified. Costal short-cells conspicuously in long rows, or neither distinctly grouped into long rows nor predominantly paired (over the minor veins). Costal silica bodies ‘panicoid-type’.

Transverse section of leaf blade, physiology. C4; XyMS–. PCR sheath outlines uneven. PCR sheath extensions absent. Mesophyll with radiate chlorenchyma. Leaf blade adaxially flat. Midrib conspicuous; with one bundle only. Bulliforms not present in discrete, regular adaxial groups (the epidermis extensively bulliform). Many of the smallest vascular bundles unaccompanied by sclerenchyma, or all the vascular bundles accompanied by sclerenchyma. Combined sclerenchyma girders present; forming ‘figures’. Sclerenchyma all associated with vascular bundles.

Special diagnostic feature. The inflorescence not as in Odontelytrum (q.v.).

Classification. Watson & Dallwitz (1994): Panicoideae; Panicodae; Paniceae. Soreng et al. (2015): Panicoideae; Panicodae; Paniceae; Cenchrinae. 1 species (C. hordeacea).

Distribution, phytogeography, ecology. Australia.

Mesophytic; species of open habitats. Subhumid open woodland and coastal grassland.

References, etc. Leaf anatomical: studied by us.

Illustrations. • C. hordeacea: Kunth, 1835. • C. hordeacea, abaxial epidermis of leaf blade: 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, 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: 11th December 2017.’.