4 Mr. Woops on the Genera of European Grasses. 
some of the spiculz are unproductive. These families are each divided into 
two tribes, dependent on the axis or flower-stalk, which in the one is entire 
and continuous, in the other toothed and jointed. The glumes or valves 
of the calyx are, in the first tribe, inserted alternately ; in the latter they are 
described as “ parallelle insert. Referring to the genera enumerated under 
each head, in order to find the exact force of these terms, we find all our 
one-flowered grasses in the first, except Nardus and Lepturus, together with 
Bromus, Avena, Poa, Dactylis, and some others; while Glyceria, Sclerochloa, 
Festuca, and others nearly allied are in the second. I confess myself completely 
baffled by this result, and quite unable to discover what it is which is common 
to one tribe and not to be found in the other. The tribes are divided into 
cohorts, as the spiculæ are 1- 2- or many-flowered, and as the florets are indi- 
vidually perfect or incomplete; and in the second family, according to the 
position of the separated spiculz in the same or in different panicles or spikes. 
The cohorts are variously divided into sections; and these are again sub- 
divided by means of the arms; i. e. by their absence or presence, whether 
awns or sete, rising from the extremity, near the extremity, from the back, 
or from near the base of the corolla or stragulum. What I have already said 
will show that this arrangement has the effect of widely separating genera 
very closely allied. It has also the other, of bringing together genera whose 
affinities are comparatively slight. Imperata, for instance, stands in the same 
section with Paspalum and Milium ; Erianthus is placed with Calamagrostis 
m — Sporobolus, Oryza, and Knappia occur together in another. 
ae ostis is divided into Agraulus, which is placed in the 3rd group; Vilfa, 
which is in the 6th; Agrostis in the 10th; and Apera in the 13th; Phleum 
is with Spartina and Chloris in the llth; Donax and Sesleria 
Misc d stand together 
in the 27th. The author frequently insists on his genera or groups being 
natural, but he evidently only 
means by this that each has a clear and distinct 
eR P de Manuver has introduced several new terms, and uses some 
s x z 5 ma 5 Way. Most of the writers on this part of botany 
ave acted in some degree in a similar manner. I will, therefore, before pro- 
ceeding any further explain a few of th inci 
= e princ rs, 
and as I have adopted them myself. principal, both as used by othe 
is, with P. de Beauvois, is the part of the culm, above the upper knot, 
