MR. G. BENTHAM ON GRAMINEZ, 81 
by a pappus-like ring of long hairs, give a very peculiar aspect ; 
but precisely similar flowering glumes are observable in several 
South- American species with very various habits. In the Euro- 
pean S. pennata, Linn., and a few other American as well as 
Old- World species, the awn itself is (almost entirely, or for a short 
distance above the base) plumose with long spreading hairs. 
Lasiagrostis, Link (Achnatherum, Beauv.), was proposed as a 
genus for the European S. Calamagrostis, Wahlenb., and extended 
by Nees and Trinius to several African and Asiatic species, only 
differing from other small-flowered Stipe in the flowering glume 
itself being plumose with spreading hairs, either below the middle 
or in its whole length;.and in AS. mongholica, Trin., forming the 
genus Ptilagrostis of Grisebach, these hairs extend to halfway up 
theawn. S. verticillata, Nees, from Australia, and Apera arundi- 
nacea, Hook. f., from New Zealand, two plants closely resembling 
each other, though specifically distinct, connect Stipa with Mueh- 
lenbergia. They have the inflorescence and small spikelets of the 
latter genus; and in 5. verticillata the awn is generally persistent, 
though the articulation is distinctly traceable on the flowering 
glume; in S. arundinacea the awn is very deciduous; in this 
species there is usually but one stamen, whilst in S. verticillata 
there are the normal three. S. rariflora (Muehlenbergia rariflora, 
Hook. f.), from Antarctic America, is another species closely 
allied to the above two; and all three appear to be better placed 
under Stipa than under Muehlenbergia. 
3. Onvzorsis, Mich. ( Urachne, Trin.), is a genus of about four- 
and-twenty species, from the temperate and subtropical regions 
of the northern hemisphere or from extratropical South America, 
very rare within the tropics, most of them often regarded as 
awned species of Milium, but really more nearly connected with 
Stipa, from which they chiefly differ in the broader fruiting glume, 
often oblique at the top, the awn usually short, slender, and 
twisted, and very deciduous. The genus divides readily into 
three sections, regarded by some as distinct genera, but all united 
into one by Trinius and others. 1. Piptatherwm, Beauv., com- 
prises the Old-World species, often included in Milius as a 
section, with awned glumes, and really connecting in some mea- 
sure the two genera. The obliquity of the fruiting glume is 
much less marked than in the typical species of Oryzopsis; and 
the rhachilla of the spikelet is glabrous. 2. Eworyzopsis or 
Oryzopsis proper, including the proposed genera Caryochloa, 
