we 
: te “PRIANDRIA. DIGYNGA. | 61 
ae frequently sheathed by cymbiform acute or acuminated 
__ . leaves, in some species so closely as not to admit the ex- 
_pansion of the spikes; flowers alternate and sessile, with 
lateral abortive pedicellate florets, sometimes mere bar- _ 
pedicells, arising near their base. In the American’ 
the inyolucrate villus is often short, sometimes 
~ Anconspicuous. re ‘ 
“4 ‘ ~ SPEGIES. 1. A. nutans. 2. avenaceum. §. ciliatum, Ex. 
4 melanocarpus, Hu. 5. scoparium. 6. macrourum. 7. terna=— 
 vium 8, virginicum. 9. bicorne. 10. argenteum, Ex... dA. 
 dissitiflorum 12, vaginatum, Ex. 13. tetrastuchyum, Ex. 
44. furcatum. — . a 
-. In India there are 11 species of this genus, 2 of which, 
the A. Nardus and A. muricatum, are every where culti- 
; vated for their aromatic odour. ‘There are also 3 species 
+. inJapan, 5 in the south of Europe, most of which are also — 
* ~ indigenous to Barbary, 1 species peculiar to that country, 
and 1 at the Capeof Good Hope,,2 in the West India- 
». __ islands, and now 14 species enumerated in the United 
a i, States, of which, severai are also common to the tropical 
regions of the American continent. Excepting the con- 
< tinent of India, there appears not to exist a single genu- 
ine species of Andropogon, within the southern hemis- 
phere. 
§ 11. Calices 2-flowered, dispersed. 
$89. TRISETUM. Persoon. (Three-awned Oat- 
grass.) 
Calix 2 to $-flowered, acuminate and cari- 
nate. Corolla, (outer valve) terminated by 2— 
shorter, almost tooth-like awns (or the apex of 
the glume setaceously bifid,) and 1 longer 
straight dorsal awn, not contorted. ae 
Species of Avena of other authors, distinguished chief- 
ly by a deeply cleft acum/nate and carinate dorsal valve, 
; a central straight awn, with compressed pale coloured 
' spikelets, and floseuli which are generally smooth, — 
Specigs. 1. I pratense, (Avena flavescens, L.) The rest — 
* of this genus is chiefly confined to the South of Europe, 
: Barbary, and the Cape of Good Hope. 
90. AIRA, L. (Hair-grass.) = 
Calia shining, 2-valved, 2-flowered. C 
~ awnless, or awned from the base, 2-vaived. 
= so Pics, G P i 
oS ie : 
