289 



MOSS-FLORA OF ARKENGARTHDALE. 



WILLIAM INGHAM, B.A., 

 Organising Inspector of Schools, Haxby Road, York. 



I propose in this paper giving the most interesting Mosses 

 collected at the meeting of the Yorkshire Naturalists' Union, 

 4th August to 6th August 1900. The time was too short to do 

 anything like justice to the moss-flora of such an interesting 

 dale, and, as the members present know only too well, the 

 conditions for gathering were rather too moist even for a 

 bryologist, who grows to love moisture and its effects. 



On a future occasion I hope to send a complete list of the 

 mosses, both common ones and rare ones. 



En route to Farngill, Dicranoweisia cirrata Ldb., crowded 

 with fruit, was frequent on the wall tops ; also Hypnum unci- 

 natum Hedw. By the banks of the gill, A mblystegium filicihum 

 DeNot. was very abundant, forming extensive patches, but 

 nowhere in fruit. This is by far the most abundant moss in 

 Arkendale. Its frequent companions Hypnum commiitatnm and 

 Hypnum falcatum were also very abundant and conspicuous, but 

 only a little fruit was found on the former. Higher up the gill 

 I found a beautiful, dwarf, and vivid green variety of Weisia 

 rupestris covered with capsules. This is probably a new variety, 

 as it is different from the very many specimens of IV. rupestris 

 I possess. Close by I was pleased to find the rare Grimmia 

 a [fin is Lindb., the Rhacomitrium heterostichum var. alopecuru?n 

 Hi'ibn. of Dixon's ' Handbook of British Mosses.' 



At the head of the gill I traversed extensive tracts of moor- 

 land and nowhere saw any deep Sphagnum swamp. It was 

 Interesting to compare the shallow sheets of the bog-mosses 

 w ith the thin strata of coal that Mr. Goodchild pointed out exist 

 now under the surface. On this moor I found a long growth of 

 the rare moss Hypnum strain incum. One shallow pool was 

 covered with H. Jluitans var. falcatum Schp., the true 'fal- 

 catum,' so easy to mistake for other mosses until properly 

 understood. There was no fruit, whereas in a similar pool on 

 the top of Burnhope Seat, in Durham, I found- one mass of 

 capsules in July 1898. The Sphagna observed were all the 

 common ones — SpJiagnum cuspidatum, S. intermedium , S. acuti- 

 folium, and S. papillosum — except one, which has still to be 

 determined. 



1900 October 1. T 



