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 soderstromii

HABIT Perennial; caespitose. Culms 10–18 cm long; 1–2 -noded. Culm-internodes smooth. Lateral branches lacking. Leaf-sheaths open for most of their length; with 0.33–0.5 of their length closed; 7.5–8.5 cm long; glabrous on surface. Ligule an eciliate membrane; 2–4 mm long; erose; acute. Leaf-blades conduplicate; 4.2–5 cm long; 2 mm wide. Leaf-blade surface smooth; glabrous. Leaf-blade margins scabrous. Leaf-blade apex acute.

INFLORESCENCE Inflorescence a panicle; shorter than basal leaves; embraced at base by subtending leaf. Peduncle 2–4.5 cm long.

Panicle contracted; elliptic; 4.5–6 cm long; 1–2 cm wide; bearing few spikelets; with spikelets clustered towards branch tips. Primary panicle branches 2 -nate; 0.9–2 cm long; bearing 5–6 fertile spikelets on each lower branch.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 0.5 mm long; scabrous.

FERTILE SPIKELETS Spikelets comprising 2–3 fertile florets; without rhachilla extension. Spikelets oblong; laterally compressed; 2.8–3.2 mm long; 1–2 mm wide; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 0.4–0.5 mm long; glabrous. Floret callus glabrous, or woolly.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume oblong; 2.8–3 mm long; 1 length of upper glume; membranous; 1-keeled; 1–3 -veined. Lower glume primary vein scabrous. Lower glume lateral veins absent, or distinct. Lower glume apex acute. Upper glume oblong; 2.8–3.2 mm long; 1 length of adjacent fertile lemma; membranous; 1-keeled; 3(–5) -veined. Upper glume primary vein scabrous. Upper glume lateral veins prominent. Upper glume apex acute.

FLORETS Fertile florets alike but female above. Fertile lemma oblong; 3 mm long; membranous; keeled; 5 -veined. Lemma midvein scaberulous. Lemma lateral veins prominent. Lemma surface smooth, or granulose. Lemma apex acute. Palea 1.5–1.8 mm long. Palea keels winged; scaberulous; adorned above; with 0.66 of their length adorned.

FLOWER Anthers 3; 1–1.2 mm long.

DISTRIBUTION South America: western South America.

NOTES Poeae. Negritto & Anton 2007.

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