GrassBase - The Online World Grass Flora


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

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

Poa diaboli

HABIT Perennial; caespitose; clumped loosely. Rhizomes elongated. Stolons present. Basal innovations extravaginal, or intravaginal. Culms geniculately ascending; 25–50 cm long; 0.5–0.9 mm diam.; with 0.33–0.5 of their length below uppermost node. Culm-internodes terete. Lateral branches sparse; arising from lower culm. Leaf-sheaths with 0.4–0.7 of their length closed; 4.5–9 cm long; keeled; scaberulous. Ligule an eciliate membrane; 1–3 mm long; scaberulous on abaxial surface; truncate, or obtuse, or acute. Leaf-blades flat, or conduplicate; 2.6–11 cm long; 0.8–2 mm wide. Leaf-blade venation prominent. Leaf-blade margins scabrous. Leaf-blade apex hooded.

INFLORESCENCE Monoecious; gynomonoecious with sex changing according to season. Inflorescence a panicle.

Panicle open; ovate, or pyramidal; 4–10.5 cm long. Primary panicle branches ascending, or spreading; 1–2 -nate; 2.1–7 cm long. Panicle branches scabrous.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising (2–)3–6(–7) fertile florets; with diminished florets at the apex. Spikelets lanceolate; laterally compressed; 5.3–9 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 1–1.3 mm long; eventually visible between lemmas; smooth, or scaberulous. Floret callus woolly.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume lanceolate; 2–3.8 mm long; 1 length of upper glume; membranous; 1-keeled; 3 -veined. Lower glume apex acute. Upper glume lanceolate; 2.3–3.9 mm long; 0.75 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume apex acute.

FLORETS Fertile florets bisexual, or female. Fertile lemma lanceolate; 3.2–5 mm long; membranous; much thinner on margins; keeled; 5 -veined. Lemma lateral veins prominent. Lemma surface asperulous; glabrous. Lemma apex acute; muticous, or mucronate. Palea 0.8–1 length of lemma. Palea keels scabrous. Palea surface asperulous. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; lanceolate; 1 mm long; membranous. Anthers 3; 1.4–2.6 mm long. Ovary glabrous.

FRUIT Caryopsis with adherent pericarp. Hilum punctiform.

MALE Male inflorescence similar to female. Male spikelets similar to female but less developed.

DISTRIBUTION North America: southwest USA.

NOTES Poeae. Soreng & Keil 2004.

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