426 MR. G. C. DRUCE ON A NEW SPECIES OF GRASS, 
/ 
On a New Species of Grass, Bro interruptus, in Britain. By 
G. CLaripce Dr¥ce, M.A., F.L.S. 
[Read 5th December, 1895.] 
Tue history of the species is as follows :—In 1888 I found what 
I thought was a peculiar variety of Bromus mollis occurring in 
considerable quantity in a barren chalky field, in which a crop 
of barley had been sown the preceding year, but which was 
then lying fallow. The field is situated on the Lower Chalk 
formation between Unwell Wood and Blewburton Camp, in 
Berkshire. In the adjoining fields B. mollis var. glabrescens 
occurred more frequently than the ordinary form. Subse- 
quently I found the same peculiar form in smaller quantity, 
in a clover field on the same geological formation on the 
Oxfordshire side of the river, between Goring and Gathampton. 
An examination of our herbaria and of botanical works having 
failed to yield anything like these specimens, I sent a supply to 
the Botanical Exchange Club in 1888, under the name of 
B. mollis var. aggregatus. One of these Berkshire specimens 
was sent to Professor Hackel so lubelled. He quite agreed in 
considering it a new variety, and while offering to retain my 
Suggested name thought that the name interruptus would be 
more suitable, to which I willingly acceded. Professor Hackel 
diagnosed it as follows :—<‘ B. mollis L. var. interrupta, mibi 
(Hackel). Panicula brevis, interrupta, spiculis glomeratis 
obovato-ellipticis, gluma sterili Superiore dimidiam spiculam 
equante vel superante. Affinis B. molli var. conglomerato, 
Persoon, Syn. i. p- 8, cujus panicula equaliter compacta, 
spicule angustiores, villosiores.” 
For the last seven years I have kept the plant under obser- 
vation. I find it comes true from seed, and it is fairly persistent 
in its localities. It must be borne in mind that so far it has 
only been met with in arable ground. It is by no means 
contined to the two fields where I first discovered it in 1888, 
but is found over a considerable area of the Lower Chalk 
cornfields, 
This season it was very abundant in a field of vetches near 
Upton, in Berkshire. From the result of my observations I was 
led to believe it to be at least sub-specifically distinct from 
B. mollis, and I had described it as a species in my forthcoming 
