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The grass genera of the world

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

Leptosaccharum (Hackel) A. Camus

~ Eriochrysis

Habit, vegetative morphology. Perennial; caespitose. Culms 40–70 cm high; herbaceous; unbranched above. Culm nodes hairy. Leaves mostly basal; non-auriculate. Sheath margins free. Leaf blades narrow; 1.5–2 mm wide; setaceous; without cross venation. Ligule a fringe of hairs; 1–1.5 mm long.


Inflorescence. Inflorescence paniculate; contracted (narrow). Inflorescence with axes ending in spikelets. Inflorescence espatheate; not comprising ‘partial inflorescences’ and foliar organs. Spikelet-bearing axes ‘racemes’; solitary; persistent (distinctly articulated, but tenacious?). ‘Articles’ densely long-hairy (with conspicuous tufts of golden hairs at each joint and beneath each spikelet). Spikelets not secund; consistently in ‘long-and-short’ combinations (but irregularly so). The ‘shorter’ spikelets hermaphrodite. The ‘longer’ spikelets hermaphrodite.

Female-fertile spikelets. Spikelets unconventional (because they have only one glume, with reduced L2 and P2); 4–7 mm long; compressed dorsiventrally; falling with the glumes. Rachilla terminated by a female-fertile floret. Hairy callus present.

Glumes one per spikelet; long relative to the adjacent lemmas; hairy; not pointed; awnless; non-carinate. Upper glume 3 nerved. Spikelets with incomplete florets. The incomplete florets proximal to the female-fertile florets. The proximal incomplete florets 1; epaleate; sterile. The proximal lemmas awnless; 3–5 nerved; decidedly exceeding the female-fertile lemmas; decidedly firmer than the female-fertile lemmas (hairy, similar to the glume); not becoming indurated.

Female-fertile florets 1. Lemmas greatly reduced; less firm than the glumes (flimsy); not becoming indurated; entire; pointed; awnless; hairy; non-carinate; having the margins lying flat on the palea; without a germination flap; 0–1 nerved. Palea present (but reduced, similar to the L2); conspicuous but relatively short; awnless, without apical setae; textured like the lemma (flimsy); not indurated; nerveless; keel-less. Lodicules present; 2; free; fleshy (large); glabrous; not or scarcely vascularized. Stamens 3 (very small, shorter than the lodicules). Anthers not penicillate; without an apically prolonged connective. Ovary apically glabrous. Styles fused to free to their bases. Stigmas 2; red pigmented.

Fruit, embryo and seedling. Fruit small. Pericarp fused. Embryo large.

Abaxial leaf blade epidermis. Costal/intercostal zonation lacking. Papillae absent. Mid-intercostal long-cells rectangular; having markedly sinuous walls. Microhairs absent. Stomata absent or very rare; 22.5–27 microns long. Subsidiaries triangular. Guard-cells overlapping to flush with the interstomatals. Intercostal short-cells common; in cork/silica-cell pairs (no zonation, but pairs everywhere). Costal short-cells predominantly paired. Costal silica bodies tall-and-narrow, crescentic, and oryzoid (intergrading); not sharp-pointed.

Transverse section of leaf blade, physiology. C4; XyMS– (but bundles variable). Mesophyll with radiate chlorenchyma. Leaf blade with distinct, prominent adaxial ribs; with the ribs very irregular in sizes. Midrib conspicuous; having a conventional arc of bundles; with colourless mesophyll adaxially. Bulliforms not present in discrete, regular adaxial groups. All the vascular bundles accompanied by sclerenchyma. Sclerenchyma not all bundle-associated. The ‘extra’ sclerenchyma in a continuous abaxial layer.


Distribution, phytogeography, ecology. Brazil & Paraguay.

References, etc. Morphological/taxonomic: Camus 1923. Leaf anatomical: this project.

