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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 archeri
HABIT Perennial; caespitose. Culms erect; 60–120 cm long; 1–3 mm diam.; 2–4 -noded; not swollen at the base, or swollen at the base; forming an ovoid corm. Culm-internodes terete; ridged; smooth, or scaberulous. Culm-nodes glabrous. Leaf-sheaths ribbed; smooth. Ligule an eciliate membrane; 4.5–12.5 mm long; acute. Leaf-blades flat, or involute; 15–32 cm long; 2.5–4 mm wide. Leaf-blade surface ribbed; grooved adaxially and abaxially; smooth, or scaberulous; rough abaxially; pubescent; hairy adaxially.
INFLORESCENCE Inflorescence a panicle.
Panicle open, or contracted; 15–35 cm long. Primary panicle branches 2–3 -nate; 7–15 cm long.
Spikelets solitary. Fertile spikelets pedicelled.
FERTILE SPIKELETS Spikelets comprising 3–7 fertile florets; with a barren rhachilla extension, or with diminished florets at the apex. Spikelets oblong; laterally compressed; 12–18 mm long; breaking up at maturity; disarticulating below each fertile floret.
GLUMES Glumes persistent; similar; shorter than spikelet; thinner than fertile lemma. Lower glume lanceolate; 5.1–6.8 mm long; 0.75 length of upper glume; membranous; 1-keeled; 3–5 -veined. Lower glume apex acute, or acuminate. Upper glume elliptic; 6.4–9.2 mm long; 1.1–1.2 length of adjacent fertile lemma; membranous; 1-keeled; 5–7 -veined. Upper glume apex acute; muticous, or mucronate.
FLORETS Fertile lemma elliptic; 6–7.8 mm long; cartilaginous; without keel; 7 -veined. Lemma surface smooth, or scabrous. Lemma apex dentate; 4 -fid; with lobes 2–3 mm long; awned; 5 -awned. Principal lemma awn dorsal; arising 0.55–0.6 way up back of lemma; geniculate; flat below; 14.5–17.5 mm long overall; with 9–12 mm long limb; with twisted column. Column of lemma awn 5–7.5 mm long; scabrous. Lateral lemma awns arising on apex of lobes; 0.5–0.8 mm long; shorter than principal. Palea 0.65–0.7 length of lemma. Palea keels ciliate. Palea surface smooth, or papillose. Apical sterile florets resembling fertile though underdeveloped.
FLOWER Lodicules 2; 1.4–1.9 mm long; membranous; glabrous; acute. Anthers 3; 2.3–2.4 mm long; eventually exserted, or retained within floret. Ovary glabrous.
FRUIT Caryopsis with adherent pericarp; 1.7–2.2 mm long; light brown; glabrous. Embryo 0.2–0.3 length of caryopsis. Hilum linear; 0.3–0.35 length of caryopsis.
DISTRIBUTION Australasia: Australia.
NOTES Aveneae. Jacobs & Lap 1994.
Please cite this publication as detailed in How to Cite Version: 3rd February 2016.
