GrassBase - The Online World Grass Flora

Descriptions

W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Iseilema fragile

HABIT Annual; caespitose. Culms erect, or geniculately ascending; 10–20 cm long. Lateral branches ample. Leaf-sheaths keeled; antrorsely scabrous. Ligule an eciliate membrane, or a ciliolate membrane; 0.75 mm long. Leaf-blades conduplicate; 3–7 cm long; 2–4 mm wide. Leaf-blade surface scaberulous; rough on both sides. Leaf-blade apex acute.

INFLORESCENCE Synflorescence compound; paniculate; 1–3 cm long; with simple branching (1 raceme per spatheole). Inflorescence composed of racemes; terminal and axillary; deciduous as a whole; subtended by a spatheole; enclosed. Spatheole linear; 0.8–1.2 cm long; coriaceous; without tubercles. Peduncle 0.1 cm long; smooth; glabrous; disarticulating; disarticulating below uppermost sheaths.

Racemes 1; single; linear; 0.8 cm long; bearing few fertile spikelets; bearing 1 fertile spikelets on each. Rhachis glabrous on surface. Rhachis internodes linear; 1 mm long.

Spikelets in threes (basal paired). Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 2 in the cluster. Pedicels filiform; 3–3.5 mm long; puberulous.

STERILE SPIKELETS Basal sterile spikelets represented by a single scale (vestige of pedicel & spikelet); 4 in number; forming an involucre about the fertile; with both pairs arising at about the same level; subsessile; deciduous with the fertile; 0.1 mm long; smaller than fertile.

Companion sterile spikelets well-developed; comprising 2 unequal glumes without lemmas, or comprising 2 subequal glumes without lemmas, or containing empty lemmas, or male (1 developed, 1 reduced); lanceolate; 0–4.2 mm long; shorter than fertile; separately deciduous. Companion sterile spikelet glumes membranous; 4–6 -veined; glabrous; muticous. Companion sterile spikelet lemmas 2; enclosed by glumes.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; acuminate; 7 mm long; falling entire; deciduous with accessory branch structures.

GLUMES Glumes dissimilar; firmer than fertile lemma. Lower glume elliptic; 1 length of spikelet; cartilaginous; without keels; keel-less except near apex; 8 -veined. Lower glume apex emarginate. Upper glume lanceolate; 1 length of spikelet; coriaceous; 3 -veined.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret lanceolate; 4–4.2 mm long; hyaline; obtuse. Fertile florets female. Fertile lemma linear; 5 mm long; membranous; 1 -veined. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 16–18 mm long overall; with twisted column. Column of lemma awn glabrous. Palea absent or minute.

FRUIT Caryopsis oblong; 3.75 mm long.

DISTRIBUTION Australasia: Australia.

NOTES Andropogoneae. Blake.

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