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.

Poa helenae

HABIT Perennial; caespitose. Basal innovations extravaginal and intravaginal. Culms erect; 12–17 cm long. Lateral branches lacking. Leaves mostly basal. Ligule an eciliate membrane; 0.75–1.75 mm long; glabrous on abaxial surface, or scaberulous on abaxial surface; acute. Leaf-blades erect; filiform; involute; 4–6.5 cm long; 0.4–1 mm wide; stiff. Leaf-blade surface smooth. Leaf-blade apex acute.

INFLORESCENCE Inflorescence a panicle.

Panicle open; elliptic; 1.8–3.5 cm long; 0.5–1 cm wide. Primary panicle branches ascending; 2 -nate; 0.9–1.1 cm long; bearing 3–7 fertile spikelets on each lower branch. Panicle branches scaberulous.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; with a barren rhachilla extension. Spikelets oblong; laterally compressed; 1.8–2 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus glabrous.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume lanceolate; 1–1.25 mm long; 1 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume surface asperulous; rough on veins. Lower glume apex acute. Upper glume ovate; 1–1.3 mm long; 0.66–0.75 length of adjacent fertile lemma; membranous; 1-keeled; 1(–3) -veined. Upper glume lateral veins absent, or obscure. Upper glume surface asperulous; rough on veins. Upper glume apex acute.

FLORETS Fertile lemma ovate; 1.6–1.75 mm long; membranous; keeled; 3 -veined. Lemma midvein scaberulous. Lemma surface asperulous. Lemma apex acute. Palea keels scaberulous. Rhachilla extension 0.25 mm long.

FLOWER Lodicules 2; membranous. Anthers 3; 0.6 mm long.

FRUIT Caryopsis with adherent pericarp. Hilum punctiform.

DISTRIBUTION Asia-tropical: Papuasia.

NOTES Poeae. Veldkamp 1995.

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