栏目

唐氏早熟禾Poa tangii Hitchc.

唐氏早熟禾Poa tangii Hitchc.

别名:普通早熟禾;长药早熟禾;色古得日音-伯页力格-额布苏;

科名:禾本科 Gramineae

属名:早熟禾属 Poa

《中国植物志》第9(2)卷124页
  46.唐氏早熟禾(禾本科图说)
  Poa tangii Hitchc. in Proc. Biol. Soc. Washington 43: 94. 1930;中国主要植物图说·禾本科204, 图158. 1959.
  多年生,具匍匐的细长根状茎。秆直立,高约50厘米,细弱,具2节,上部长露出鞘外。叶鞘下部2/3闭合,长于其叶片,平滑;叶舌截平,长约1毫米;叶片扁平,柔软,宽2-3毫米,茎生者长2-4厘米,蘖生者长约10厘米。圆锥花序疏展,长5-8厘米,分枝孪生,长2-4厘米,平滑细弱,先端着生2-3个小穗,下部长裸露;小穗含3-6小花,长7-8毫米,宽约3毫米,灰绿色,质地薄;小穗轴细长而外露;第一颖狭披针形,长3-3.5毫米,具1脉,第二颖长4.5-5毫米,宽约2毫米;外稃长圆形,长4-5毫米,先端钝,与边缘均具透明宽膜质,脉间微粗糙,脊与边脉下部1/4具柔毛,基盘有绵毛;内稃近等长于外秤,两脊上部微粗糙;花药大,长3-3.5毫米。花期5-7月。
  产山西、河北。生于林缘湿草地,海拔1700米。模式标本采自山西平遥。

《Flora of China》 Vol. 22 (2006)
Poa tangii  Hitchcock
唐氏早熟禾   tang shi zao shu he
Poa shansiensis Hitchcock.
Perennials, loosely tufted, sometimes short rhizomatous; shoots mainly extravaginal. Culms erect, sometimes abruptly decumbent at base, few per tuft, 25–50 cm tall, 0.5–1 mm in diam., smooth, nodes 2 or 3, 1 or 2 exserted, uppermost usually 1/3–1/2 way up. Lower leaf sheaths mostly 1.2–1.5 mm wide, with well-spaced moderately raised ribs, thin between the ribs, smooth or scabrid, sometimes hispidulous, lowermost ones not closely overlapping, papery, withering, longest 4–10 cm, smooth, glabrous, 2–4 × as long as blade, uppermost closed for 2/5–3/4 of length; blade flat, papery to thickly papery, 2–4(–10) cm × 1–2(–3) mm, abaxially smooth, adaxially smooth or scabrid, glabrous, margins finely scabrid, of tillers flat or folded, 5–20 cm, generally with only primary veins expressed abaxially (3–5 veins visible including keel); ligule 0.5–1 mm, apex truncate, errose to fimbriate, adaxially smooth or scabrid, collar margins not or weakly flared, smooth or scabrid, glabrous or the lower ones sometimes ciliate. Panicle open, erect or lax, diffuse, exserted, 2–8 × 2–4 cm, longest internodes 1.2–3.5 cm; branches spreading, 2 per node, slender, rounded, smooth, longest 1.5–4 cm with 1–3 spikelets in distal 1/3; flowers female or perfect, sometimes whole inflorescences female. Spikelets ovate, grayish green, 5–8 mm, florets 3–6; vivipary absent; rachilla internodes 0.7–2.5 mm, smooth or sparsely scabrid, glabrous or sparsely pilulose; glumes very thinly papery, surface smooth, keel smooth or sparsely scabrid, apex obtuse to acute, blunt or pointed, lower glume lanceolate, 2.5–3.5 mm, 1/2–3/4 as wide as upper, 1-veined, upper glume 3–5.5 mm, 3-veined; lemmas oblong, very thinly papery, 4–5.5 mm, apex obtuse, veins glabrous or keel loosely villous for 1/2 of length, marginal veins to 1/3, area between veins smooth or distally scabrid, proximally glabrous or laxly pilulose; callus webbed or diffusely hairy, hairs less than 1/2 as long as lemma; palea, smooth or minutely bumpy (or with sparse minute hooks), glabrous between keels, keels sparsely scabrid, sometimes medially pilulose. Anthers 2.5–3.5 mm, or vestigial. Fl. and fr. May–Jul.
* Wet grassy places along forest margins; 1500–3600 m. Gansu, Hebei, Nei Mongol, Qinghai, Shanxi.
Poa tangii is variable in spikelet pubescence, but the variation is not geographically correlated. The species becomes especially difficult to distinguish from P. polycolea in Gansu and Qinghai, except by its smooth, rounded branches and sparsely scabrid palea keels. Compare P. tangii also with P. veresczaginii in P. subg. Ochlopoa.

TOP