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.

Helictotrichon pubescens

HABIT Perennial; caespitose. Rhizomes short. Butt sheaths dark brown. Culms erect, or geniculately ascending; 30–100 cm long; 2–3 -noded. Leaves mostly basal. Leaf-sheaths hirsute. Ligule an eciliate membrane; 4–8 mm long. Leaf-blades 4–30 cm long; 2–6 mm wide. Leaf-blade venation distinct. Leaf-blade surface pubescent.

INFLORESCENCE Inflorescence a panicle.

Panicle open; lanceolate, or oblong; equilateral, or nodding; 10–18 cm long; 2–6 cm wide. Primary panicle branches bearing 1–3 fertile spikelets on each lower branch. Panicle branches scaberulous.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 4–20 mm long.

FERTILE SPIKELETS Spikelets comprising 2–3 fertile florets; with a barren rhachilla extension. Spikelets oblong; laterally compressed; 11–17 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes villous; hairy above; with 4–7 mm long hairs. Floret callus pilose.

GLUMES Glumes persistent; similar; shorter than spikelet; thinner than fertile lemma; shiny. Lower glume lanceolate; 7–13 mm long; 0.7–0.8 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume lanceolate; 10–15(–17) mm long; 1.1 length of adjacent fertile lemma; membranous; with hyaline margins; 1-keeled; 3 -veined. Upper glume apex acute.

FLORETS Fertile lemma oblong; 9–14 mm long; chartaceous, or cartilaginous; without keel; 5 -veined. Lemma surface scaberulous; rough above. Lemma apex erose; obtuse; awned; 1 -awned. Principal lemma awn dorsal; arising 0.5 way up back of lemma; geniculate; 12–20 mm long overall; with twisted column. Palea 0.8–0.9 length of lemma. Palea keels eciliate. Rhachilla extension 0.66–0.75 length of fertile floret; villous.

FLOWER Anthers 3; 4.5–6.5 mm long. Ovary pubescent on apex.

FRUIT Caryopsis with adherent pericarp; hairy at apex. Hilum linear.

DISTRIBUTION Europe: northern, central, southwestern, southeastern, and eastern. Asia-temperate: Siberia, Soviet Middle Asia, Caucasus, western Asia, China, and Mongolia. North America: eastern Canada and northeast USA.

NOTES Aveneae. TAC.

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