Psilolemma jaegeri

HABIT Perennial; mat forming. Cataphylls evident. Stolons present. Butt sheaths thickened and forming a bulb; yellow; glossy; glabrous. Culms erect; 7–35 cm long; wiry. Culm-nodes brown. Lateral branches sparse. Leaves cauline; distichous. Leaf-sheaths longer than adjacent culm internode; wider than blade at the collar; smooth; glabrous on surface. Ligule a fringe of hairs; 0.3–0.75 mm long. Leaf-blades convolute; 0.5–7 cm long; 1.5–2 mm wide; stiff. Leaf-blade surface ribbed; papillose. Leaf-blade apex acute; pungent; smooth.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 1–6; single (when depauperate), or borne along a central axis; appressed; 1–4 cm long; bearing few fertile spikelets; bearing 1–5 fertile spikelets on each. Central inflorescence axis 3.5–12 cm long. Rhachis subterete. Spikelet packing broadside to rhachis; lax; irregular.

Spikelets ascending; solitary. Fertile spikelets pedicelled, or sessile. Pedicels linear; 0–3 mm long.

FERTILE SPIKELETS Spikelets comprising 4–14 fertile florets; with diminished florets at the apex. Spikelets linear; laterally compressed; compressed slightly; 5–15 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes definite; eventually visible between lemmas. Floret callus evident; 0.1 mm long.

GLUMES Glumes persistent; similar; subequal in width; shorter than spikelet; thinner than fertile lemma. Lower glume lanceolate to ovate; 1.2–3 mm long; 0.6–0.8 length of upper glume; hyaline; without keels; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume ovate; 2.3–3 mm long; 0.6–0.8 length of adjacent fertile lemma; hyaline; without keels; 1 -veined. Upper glume lateral veins absent. Upper glume apex obtuse, or acute.

FLORETS Fertile florets free at tip. Fertile lemma oblong; laterally compressed; 3–3.8 mm long; membranous; without keel; 3 -veined. Lemma lateral veins midway between midvein and margin; stopping well short of apex. Lemma apex emarginate (rarely), or obtuse. Palea oblong; 0.9 length of lemma; 2 -veined. Palea apex entire; obtuse. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Anthers 3; linear; 1.7–2 mm long. Stigmas 2.

FRUIT Caryopsis with tardily free pericarp; ellipsoid; isodiametric; biconvex; without sulcus; 1.1–1.2 mm long. Embryo 0.4 length of caryopsis. Disseminule comprising a floret.

DISTRIBUTION Africa: west-central tropical and east tropical.

NOTES Eragrostideae. WDC.

Please cite this publication as detailed in How to Cite Version: 3rd February 2016.