125 
POA IRRIGATA LINDMAN IN BRITAIN. 
G. CLARIDGE DRUCE, 
Two years ago Professor Lindman, of Stockholm, sent me his 
description of the above plant, which appeared in the 
‘ Botaniska Notiser ’ for 1905, and he also told me about it 
during our long journey with the International Phyto-geo- 
graphical Excursion through the British Isles in 1911, when, 
however, he saw nothing he was able to refer to it, albeit the 
extraordinary dry weather of that year was quite unfavourable 
for the collection of grasses, which were well nigh over at that 
time. But from what he told me I felt quite certain it would 
be found to be included in my large collection of Poa pratensis. 
When Professor Lindman was staying with me recently he 
was unhesitatingly able to name several plants in my her- 
barium as this species. In each case they had been marked 
by me as a variant of the aggregate Poa pratensis. The 
earliest one was gathered in 1889, at Padworth in Berkshire, 
when I thought it was a distinct form, but Hackel put it under 
pratensis, and as a forma umbrosa of that species it is alluded 
to in my ‘ Flora of Berkshire ’ (page 580, 1897). This is not 
typical irrigata, but Lindman’s forma ancta, a larger and 
more lowland plant. The first published reference to it is, 
I believe, to be found in the ‘ Annals of Scottish Natural 
History ’ (1895, page 37). A curious form of the pratensis 
group which I gathered on the Cnochan rocks (an interesting 
portion of country mentioned by Lightfoot in his ‘ Flora 
Scotica ’ as the habitat of Dysar and other rare plants, which 
extends into both Ross and Sutherland), gave me considerable 
trouble, for it was quite new to me, and, indeed, so different 
was it from P. pratensis that one of our best botanists named 
it Poa glauca. Eventually Professor Hackel considered it 
best to refer it to Poa humilis Ehrh., a definition which, as 
we shall see, was extremely close to the truth. In the same 
year, and also in 1896, I gathered an allied — although not 
identical — plant in small quantity high up on Ben Lawers. 
This excited a great amount of interest, for the gathering 
(No. 2512) was at first referred to P. cenisia var. flexuosa 
Wahl., by Professor Hackel, and as such I recorded it [l.c. 122 
(1898)]. On subsequently comparing it with authentic speci- 
mens of flexuosa from the Dovrefeld I felt they must be 
distinct. Therefore, in July 1898 I again visited Ben Lawers, 
when only a few specimens identical with 2512 .were ob- 
tained, although many others were closely allied to it. At 
that time Mr. H. Fisher was paying some attention to the 
genus Poa, so I sent him all my gathering, when he also 
determined 2512 to be P. cenisia, var. arctica R. Br., but 
1914 April 1. 
