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The grass genera of the world

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

Streblochaete Hochst.

Including Koordersiochloa Merr., Pseudostreptogyne A. Camus

Habit, vegetative morphology. Perennial; caespitose. Culms 30–100 cm high; herbaceous; unbranched above. Leaves non-auriculate. Sheath margins joined. Leaf blades linear-lanceolate; rolled; without cross venation. Ligule an unfringed membrane; not truncate; 3–12 mm long.

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

Inflorescence. Inflorescence paniculate; open (narrow); espatheate; not comprising ‘partial inflorescences’ and foliar organs. Spikelet-bearing axes persistent. Spikelets secund to not secund (the panicle sometimes unilateral), or not secund; pedicellate.

Female-fertile spikelets. Spikelets 16–28 mm long; not noticeably compressed; disarticulating above the glumes; disarticulating between the florets. Rachilla prolonged beyond the uppermost female-fertile floret; the rachilla extension with incomplete florets. Hairy callus present. Callus long; pointed.

Glumes present; two; very unequal; shorter than the spikelets; shorter than the adjacent lemmas; hairless; pointed; awnless; non-carinate (rounded dorsally); similar (narrow, membranous-herbaceous with hyaline margins). Lower glume 3 nerved. Upper glume 5 nerved (with transverse linking). Spikelets with incomplete florets. The incomplete florets distal to the female-fertile florets. The distal incomplete florets several, in a lanceolate cluster; merely underdeveloped (male or sterile).

Female-fertile florets 2–6. Lemmas similar in texture to the glumes to decidedly firmer than the glumes (herbaceous); not becoming indurated (or hardening slightly); shortly incised (to nearly entire); slightly 2 lobed; not deeply cleft; awned. Awns 1; median; dorsal; from near the top; geniculate (the very long, filiform awns coiling and intertwining with one another, so that the spikelet is dispersed as a unit); hairless (scabrid); much longer than the body of the lemma (distally filiform); entered by one vein. Lemmas hairless; non-carinate (dorsally rounded); without a germination flap; 7 nerved. Palea present; conspicuous but relatively short (about half the lemma length); apically notched; not indurated (herbaceous); 2-nerved; 2-keeled. Lodicules present; 2; free; membranous; ciliate, or glabrous; not toothed; not or scarcely vascularized. Stamens 3. Ovary apically glabrous. Styles free to their bases. Stigmas 2.

Fruit, embryo and seedling. Fruit longitudinally grooved; compressed dorsiventrally. Hilum short. Embryo small. Endosperm hard.

Abaxial leaf blade epidermis. Costal/intercostal zonation conspicuous. Papillae absent. Long-cells the costal long-cells narrower; differing markedly in wall thickness costally and intercostally (the costals thicker). Mid-intercostal long-cells rectangular; having markedly sinuous walls. Microhairs absent. Stomata absent or very rare. Intercostal short-cells common; not paired; not silicified. Prickles present over the veins. Costal short-cells neither distinctly grouped into long rows nor predominantly paired. Costal silica bodies horizontally-elongated crenate/sinuous; not sharp-pointed.

Transverse section of leaf blade, physiology. C3; XyMS+. Sclerenchyma all associated with vascular bundles.

Cytology. Chromosome base number, x = 10.

Classification. Watson & Dallwitz (1994): Pooideae; Poodae; Meliceae. Soreng et al. (2015): Pooideae; Brylkineae. 1 species (S. longiaristata).

Distribution, phytogeography, ecology. Tropical Africa, Java, Lombok, Philippines; montane.

Mesophytic; shade species; glycophytic. Montane forest glades.

References, etc. Morphological/taxonomic: Tateoka 1965b. Leaf anatomical: studied by us.

Illustrations. • S. longiaristata, as Koordersiochloa: Merrill (1917), Philippine J. of Science 12. • General morphology (S. longiarista): 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.’.