EXPERIMENTS ON THE GROWTH OF PLANTS. 203 
_ Poa.—Of this genus, among other species the two following were sown 
side by side. 
P. aquatica ( Glyceria). P. fluitans (Glyceria). 
These were sown in the autumn of 1855. During 1856 stiff and sturdy 
short-and rigid-leaved plants were forming ; these leaves were so harsh as to 
cut the flesh on the slightest touch. During the present year, 1857, they 
have flowered, and to my utter astonishment the plants of both plots are the 
same; the culms were as much as a yard in height, and the flowers so smali 
and ovate as quite to justify the retaining of the generic name of Poa for the 
whole group. 
While these grasses were flowering, I watched them from day to day with 
great interest, as in all their parts they differed so much from any known 
species; the short rigid leaves with the angular sheath, and the elegant panicle 
of flowers from their size, and the rigidity of the whole plant removed these 
far from the P. pratensis, and the whole details differed so much from the 
forms whose seed was sown as well as from all other recognised forms, that 
while it showed me I could not have mistaken my seed, it also was cou- 
vincing that I had obtained a new and singular variety. This indeed is not 
to be wondered at when we consider that both the forms, the aguatica and 
_ fluitans, absolutely grow in the water ; but here I had got them to grow in an 
upland situation, and to manage like other upland grasses with only water 
from rain. Still the change was so curious, that I was anxious to re-examine 
the seeds as sown; and fortunately some of the packets were saved, and I 
can pronounce them true as named*. 
Here then I cannct help concluding that even such dissimilar grasses as 
the typical forms of P. aquatica and P. fiuitans are not specifically distinct ; 
and though the former in its wild state bears a large and diffuse panicle of 
flowers, and the latter is almost as spicate as a Lolium, yet we may, I think, 
_ connect the evidence here presented to us with that obtained in the growth 
s of the Festuca loliacea pratensis and elatior presently to be detailed. 
__ However, I shall not conclude my experiments upon this subject without 
_ sowing some new plots with seeds of the hitherto supposed species gathered 
_ by myself for the express purpose; not that I in the least doubt these experi- 
_ ments, but in order, if possible, to note the changes more clearly t. 
Frstuca.—The species to be communicated upon I shall divide into two 
ca groups. 
S a. Festuca ovina. b. Festuca loliacea. 
»  Bduriuscula. he 19 pratensis. 
» vy rubra. » vy elatior. 
»  Otenuifolia. 
a. These were sown six years since in three distinct plots, and they soon 
_ established themselves in a separate tufted method of growth. The first two 
_ years they were readily distinguishable ; now, however, the following facts 
are observable. 
_ FF. ovina is about eighteen inches high; F’. éenuifolia, duriuscula and 
rubra differ but slightly in size, and scarcely in details, and the creeping 
habit of root of the latter is entirely lost t. 
____ It may be remarked that the F. rubra is not amongst our wild forms at 
Cirencester, but I have occasionally met with specimens of F’. duriuscala in 
____ * The two packets were sent for examination. 
~ + Specimens of the new Poas are sent for examination. 
_— t Certainly not so much as regards the width and length of the leaves, as the same form 
es on in bushes when compared with the open ground. 
