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.

Stipagrostis arachnoidea

HABIT Perennial; caespitose. Culms decumbent; 20–40 cm long. Culm-internodes distally woolly. Leaf-sheaths woolly. Ligule a fringe of hairs. Leaf-blades 9–18 cm long; 1 mm wide. Leaf-blade surface woolly; hairy abaxially.

INFLORESCENCE Inflorescence a panicle.

Panicle open; lanceolate; 10–20 cm long; bearing few spikelets.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels ciliate.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; subterete; 40–50 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus elongated; 3 mm long; pilose; acute.

GLUMES Glumes persistent; similar; exceeding apex of florets; thinner than fertile lemma. Lower glume lanceolate; 40–50 mm long; 1.5 length of upper glume; membranous; much thinner above; without keels; 7–9 -veined. Lower glume surface pilose; hairy below. Lower glume apex acuminate. Upper glume lanceolate; 30 mm long; 3 length of adjacent fertile lemma; membranous; much thinner above; without keels; 7–9 -veined. Upper glume surface pilose; hairy below. Upper glume apex acuminate.

FLORETS Fertile lemma oblong; 9.5–10.5 mm long; coriaceous; without keel; 3 -veined. Lemma margins convolute; covering most of palea. Lemma apex acute; awned; 3 -awned. Principal lemma awn 3-branched; with 70–80 mm long limb; with twisted column; deciduous; abscissing from top of lemma; limb plumose; glabrescent towards tip and base of limb. Column of lemma awn 10 mm long. Lateral lemma awns 60–70 mm long; shorter than principal; plumose. Palea 0.33 length of lemma; without keels.

DISTRIBUTION Asia-temperate: Soviet Middle Asia.

NOTES Aristideae. Fl Iran 1993.

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