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.

Jansenella griffithiana

HABIT Annual; mat forming. Culms decumbent; 15–30 cm long; rooting from lower nodes. Ligule an eciliate membrane. Leaf-blade base amplexicaul. Leaf-blades lanceolate; 1–6 cm long; 2–14 mm wide; firm, or flaccid.

INFLORESCENCE Inflorescence a panicle.

Panicle open; ovate; dense; 1–5 cm long. Panicle branches flat; scabrous; pilose.

Spikelets in pairs. Fertile spikelets pedicelled; 2 in the cluster. Pedicels unequal.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; laterally compressed; 5–7 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus pilose; obtuse.

GLUMES Glumes persistent; similar; with lower wider than upper; exceeding apex of florets; thinner than fertile lemma. Lower glume ovate; 3–4 mm long; 0.5–0.6 length of upper glume; membranous; mid-green, or purple; without keels; 3 -veined. Lower glume surface glabrous, or pilose. Lower glume apex acute; awned; 1 -awned. Lower glume awn 1 mm long. Upper glume oblong; 5–7 mm long; 1 length of adjacent fertile lemma; membranous; mid-green, or purple; without keels; 5 -veined. Upper glume surface scabrous; rough on veins; glabrous, or pilose; with tubercle-based hairs. Upper glume apex acute; awned. Upper glume awn 1–2 mm long.

FLORETS Basal sterile florets male, or barren; with palea; persisting on inflorescence. Lemma of lower sterile floret similar to upper glume; oblong; 5–7 mm long; 1 length of fertile lemma; membranous; 3–5 -veined; obtuse; awned. Awn of lower sterile floret 1–2 mm long. Palea of lower sterile floret winged on keels (narrowly). Fertile lemma oblong; 4–6 mm long; chartaceous to coriaceous; without keel; 3 -veined. Lemma surface glabrous, or pilose; with a transverse row of hair tufts; bearing 2 hair tufts in all. Lemma margins involute; interlocking with palea keels. Lemma apex lobed; 2 -fid; with triangular lobes; incised 0.3–0.4 of lemma length; awned; 3 -awned. Principal lemma awn from a sinus; geniculate; flat below; 10–15 mm long overall; with twisted column. Column of lemma awn 5 mm long. Lateral lemma awns arising on apex of lobes; 1–2 mm long; shorter than principal. Palea lanceolate; 2 -veined. Palea keels winged; narrowly winged. Palea surface pubescent; with turgid hairs. Palea apex dentate; 2 -fid.

FLOWER Lodicules 2; cuneate; fleshy. Anthers 3; 0.75–1.75 mm long. Stigmas 2.

FRUIT Caryopsis with adherent pericarp; oblong; dorsally compressed; plano-convex; 1.4–1.5 mm long. Embryo 0.5 length of caryopsis. Hilum punctiform.

DISTRIBUTION Asia-tropical: India and Indo-China.

NOTES Arundinelleae. Bor.

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