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Pakistan | Family List | Poaceae | Helictotrichon

Helictotrichon virescens (Nees ex Steud.) Henr. in Blumea. 3:425. 1940. Sultan & Stewart; Grasses W. Pak. 2:282. 1959; Bor, Grasses Burma Ceyl. Ind. Pak. 439. 1960; Bor in Rech.f., Fl. Iran. 70:332. 1970.

  • Avena aspera Munro ex Thw.
  • Avena aspera var. parviflora Hook.f.
  • Avena aspera var. roylei Hook.f.
  • Helictotrichon asperum (Munro ex Thw.) Bor
  • Helictotrichon asperum var. roylei (Hook.f.) R.R. Stewart
  • Helictotrichon parviflorum (Hook.f.) Bor
  • Helictotrichon roylei (Hook.f.) Keng
  • Trisetum virescens Nees ex Steud.

    Tufted perennial. Culms 40-120(-150) cm high, erect, slender. Leaf-blades flat, 8-35 cm long, 2-8.5 mm wide, green, scaberulous above; ligule 1-5 mm long. Panicle loose, 12-40 cm long, erect or nodding, the branches spreading or ascending, the lower 5-12(-15) cm long and with up to 12 spikelets each. Spikelets 3(-4)-flowered, oblong, 9-14(-18) mm long; glumes lanceolate to oblong-lanceolate, hyaline on the margins and at the tip, the lower 1-3-nerved, 5-9 mm long, the upper 5-nerved, 6-12 mm long; lemmas subcoriaceous with hyaline margins and tip, the lower 7.5-2.5 mm long, 5-7-nerved, scabrid all over or only on the nerves at the tip, shallowly 2-toothed to deeply bifid at the tip, the lobes sometimes acuminate or with short awn-points; awn from just above the middle, geniculate, 10-18 mm long.

    Fl. & Fr. Per.: July-August.

    Type: Northwest India, Royle 137, 138 (LIV).

    Distribution: Pakistan (Punjab, N.W.F.P. & Kashmir); Himalayas eastward to Burma and south to Sri Lanka; ? China.

    This species is common in the north between 1500 and 4000 m and is part of a complex (Avena aspera in Hooker) not easily divisible into distinct taxa. Of Hooker’s 4 varieties, only var. schmidii seems worthy of recognition and there is some justification for regarding it as a species. The remaining varieties, aspera, parviflora and roylei quite evidently merge and clearly definable boundaries between them are hard to find. Almost all material studied has lemmas that are, to some degree, scabrid. The scabridities range from pronounced spines to small white bumps of low profile, but they are rarely absent. Variation in spikelet size is also continuous. It seems better, at present, to treat this complex as a single species until any boundaries that may exist between subordinate taxa have been more precisely defined by the appropriate biosystematic techniques.


    Related Objects  
  • Illustration (S. Hameed)
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