The grass genera of the world

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

Styppeiochloa de Winter

From the Greek stuppeion (fibre) and chloa (a grass), alluding to tough, fibrous basal parts.

~ Crinipes Hochst.

Habit, vegetative morphology. Perennial; densely caespitose (the hard, fibrous basal sheaths forming tough, fire-resistant mats). Culms 10–70 cm high; herbaceous; unbranched above (wiry, the nodes hidden at the base). Culm leaf sheaths persistent, tomentose, splitting into fibres. Culm internodes solid. Plants unarmed. Young shoots intravaginal. Leaves mostly basal, or not basally aggregated; non-auriculate. Leaf blades linear; narrow; to 1 mm wide; setaceous (resembling the culms); rolled (convolute); not pseudopetiolate; without cross venation; persistent. Ligule a fringe of hairs; about 0.4 mm long. Contra-ligule absent.

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

Inflorescence. Inflorescence paniculate; contracted (scanty, the spikelets appressed to the panicle branches); espatheate; not comprising ‘partial inflorescences’ and foliar organs. Spikelet-bearing axes persistent. Spikelets pedicellate.

Female-fertile spikelets. Spikelets compressed laterally; disarticulating above the glumes; disarticulating between the florets; with conventional internode spacings. Rachilla prolonged beyond the uppermost female-fertile floret; the rachilla extension with incomplete florets. Hairy callus present. Callus short; blunt (truncate).

Glumes two; very unequal, or more or less equal; shorter than the spikelets; shorter than the adjacent lemmas; hairless; glabrous; pointed; short awned (or aristate from the excurrent mid-nerve), or awnless; carinate; similar (lanceolate, their apices 3-lobed or acute/entire). Lower glume shorter than the lowest lemma; 1 nerved. Upper glume 1–3 nerved. Spikelets with incomplete florets. The incomplete florets distal to the female-fertile florets. The distal incomplete florets merely underdeveloped; awned, or awnless. Spikelets without proximal incomplete florets.

Female-fertile florets 2–5. Lemmas similar in texture to the glumes (membranous); not becoming indurated; incised; apically 3 lobed; not deeply cleft; mucronate to awned (the three lobes with awns or mucros). Awns when present, 3; median, or median and lateral (via shortly excurrent nerves); the median similar in form to the laterals (when laterals present); apical; non-geniculate; hairless (scaberulous); much shorter than the body of the lemma; entered by one vein. The lateral awns shorter than the median. Lemmas hairy (at the margins, near the base); carinate; without a germination flap; 3–5(–7) nerved; with the nerves non-confluent. Palea present (narrowly lanceolate); relatively long (equalling the lemma); apically notched; with apical setae (via the excurrent nerves); textured like the lemma (membranous); not indurated; 2-nerved; 2-keeled (concave between the keels). Lodicules present; heavily vascularized (2–5 nerved?). Stamens 3. Anthers about 2.5 mm long; not penicillate; without an apically prolonged connective. Ovary apically glabrous; without a conspicuous apical appendage (but the style bases knob-like). Styles free to their bases. Stigmas 2.

Fruit, embryo and seedling. Fruit free from both lemma and palea; small (about 2 mm long); fusiform; not noticeably compressed (nearly terete). Hilum long-linear. Embryo small; waisted.

Ovule, embryology. Synergids not haustorial.

Abaxial leaf blade epidermis. Costal/intercostal zonation the costal and intercostal zonation fairly indistinct. Papillae absent. Long-cells similar in shape costally and intercostally; of similar wall thickness costally and intercostally. Mid-intercostal long-cells rectangular; having markedly sinuous walls. Microhairs present; panicoid-type. Stomata absent or very rare. Intercostal short-cells common. Costal short-cells conspicuously in long rows. Costal silica bodies ‘panicoid-type’; dumb-bell shaped; not sharp-pointed.

Transverse section of leaf blade, physiology. C3; XyMS+. Mesophyll with non-radiate chlorenchyma; without adaxial palisade; not Isachne-type (the cells isodiametric). Leaf blade with distinct, prominent adaxial ribs; with the ribs very irregular in sizes. Midrib not readily distinguishable; with one bundle only. Bulliforms present in discrete, regular adaxial groups (in all the furrows); in simple fans. All the vascular bundles accompanied by sclerenchyma. Combined sclerenchyma girders present (with all the large bundles); forming ‘figures’ (the large bundles). Sclerenchyma not all bundle-associated. The ‘extra’ sclerenchyma in a continuous abaxial layer.

Classification. Watson & Dallwitz (1994): Arundinoideae; Danthonieae. Soreng et al. (2015): Arundinoideae; Molinieae. 2 species.

Distribution, phytogeography, ecology. South and southeastern tropical African mountains.

Helophytic to mesophytic; species of open habitats; glycophytic. Where there is impeded drainage, in mountains.

References, etc. Morphological/taxonomic: de Winter 1966a. Leaf anatomical: photos provided by R.P. Ellis.

Illustrations. • General aspect (S. gynoglossa): Gibbs Russell et al., 1990

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.’.