All Floras      Advanced Search
Page 48 Login | eFloras Home | Help
Pakistan | Family List | Poaceae

Stipagrostis Nees in Linnaea. 7:290. 1832. Henrard in Meded. Rijks-Herb. No. 58. 1929; De Winter in Bothalia 8:307. 1965; Bor in Towns., Guest and Al-Rawi, Fl. Iraq 9:386. 1968; Bor in Rech. f., Fl. Iran. 70:368. 1970; Tzvelev, Poaceae URSS 616. 1976; Tutin in Tutin et al., Fl. Eur. 5:254. 1980.

Densely tufted perennials, suffrutices with knotty rhizomatous base, or delicate annuals. Leaf-blades narrow or terete, sometimes early deciduous leaving sheaths and chlorophyll-bearing culms as the main photosynthetic organs. Panicle open or contracted. Spikelets 1-flowered with scarious glumes; lemma cylindrical; indurated, produced into a 3-branched awn; awn with or without a column, articulated at the base of the column or near the middle of the lemma, the branches, or at least the central one plumose; callus well-developed, pungent or minutely bifid, usually oblique; palea usually less than half as long as the lemma.

A genus of about 50 species in dry or desert regions of Africa and the Middle East to Northwest India; 7 species occur in Pakistan.

Stipagrostis is readily distinguished by its plumose awns. Its separation from Aristida is supported by the following anatomical characters:

Aristida. Cells of outer bundle-sheath smaller than the inner, both sheaths containing chloroplasts; silica-bodies usually dumb-bell-shaped; chromosome number usually 2n=22.

Stipagrostis. Cells of outer bundle-sheath larger than the inner, only the inner containing chloroplasts; silica-bodies usually circular; chromosome number usually 2n=44.

1 Lowest sheaths and internodes covered with a thick flocculent fugacious wool; leaves rolled, filiform, pungent, often curved, sometimes forming a semi- circle or complete circle; central awn with an ex current naked tip   Stipagrostis plumosa
+ Lowest sheaths not lanate (or base of plant missing)   (2)
2 (1) Glumes hirsute all over or glabrous only at the tips; column bearded below the trifurcation; central branch of the awn with an excurrent naked tip   Stipagrostis hirtigluma
+ Glumes glabrous   (3)
3 (2) Central branch of the awn plumose throughout   (4)
+ Central branch of the awn plumose in the upper half or two-thirds, naked below   (5)
4 (3) Lower glume conspicuously longer than the upper; column up to 16 mm long, without a beard above and below the knee   Stipagrostis paradisea
+ Lower glume shorter than the upper or glumes sub- equal; column long-bearded above and below the knee   Stipagrostis pogonoptila
5 (3) Lemma articulated at about or just above the middle the column becoming detached at maturity together with the conical upper portion of the lemma   Stipagrostis ciliata
+ Lemma articulated at its summit, the column breaking away at maturity without a part of the lemma   (6)
6 (5) Column long-bearded at the trifurcation; articulation at the base of the column oblique   Stipagrostis uniplumis
+ Column without a beard at the trifurcation; articulation transverse; central branch of the awn without an excurrent naked tip (but if the tip is naked and excurrent see 2. S. plumose)   Stipagrostis obtusa

Lower Taxa

Related Synonym(s):


Related Objects  

Flora of China  
  • Stipagrostis.pdf
  • PDF

     |  eFlora Home |  People Search  |  Help  |  ActKey  |  Hu Cards  |  Glossary  |