26 



ON THE OCCUEEENCE 0¥ DICRANVM FLAGELLARE, 

 Hedw., IN BEITAIN. 



By E. M. Holmes. 



This species is very nearly allied to Dicranum Scoitianum, which, 

 in the dry state, it closely resembles in appearance ; hence these 

 two mosses have often been confounded. It was first described by 

 Hedwig, who gives an excellent figure of the plaut in his Muse. 

 Frond., vol. ii., t. i., fig. 1. The first record of its occurrence as a 

 British moss is by Dickson, in 1793, under the name of Bryum 

 flagellare^ in his Plant. Crypt. Brit. fasc. iii., p. 6, where he states 

 that he found the moss on rocks on Ben Nevis, and quotes Hed- 

 wig's figure. Unfortunately I have not been able to meet with 

 specimens collected by Dickson, but it is probable that they would 

 prove to belong to D. Scottianum, as D. flagellare occurs almost ex- • 

 clusively on decaying stumps of trees, and never, so far as I have 

 been able to learn, on rocks. In 1804, it was described in Turner's 

 Muse. Hibern. (p. 71) as occurring in Ireland on rocks, but no 

 locality was given. In the same year it was published in the Flor, 

 Brit. vol. iii., p. 1206, by Smith, as a British species, Dickson's 

 locality being quoted with the additional one of Cromford Moor, 

 near Matlock, where the author states that he found it, but the 

 Irish locality is not mentioned, hence it is probable that at that 

 time Smith had not seen Irish specimens. In 1809, it was figured 

 in E. B., t. 1977, the drawing of fruiting specimens being taken 

 from Irish plants, which was sent to Sir J. E. Smith, by Dawson 

 Turner, and were collected at Lough Bray. The two figures of 

 barren stems in the centre of the plate appear to have been taken 

 from the Cromford Moor specimens, since figures of the barren 

 stems do not occur in the original drawing made from Dawson 

 Turner's Irish specimens. These drawings, as well as Turner's 

 original specimens from Lough Bray, are in the British Museum, 

 and I have been permitted to examine the Irish specimens and to 

 determine that they must be referred to Dicranum Scottianum, 

 Turn. In the Bryologia Britannica, Wilson refers the left-hand 

 figure of E. B. t. 1977 to D. Scottianuvi, and states that the re- 

 puted variety of D. fiagellare, growing on Cromford Moor, is a tall 

 state of Campylopus fiexuosus. Hence, unless Dickson's plant, of 

 which Wilson takes no notice, was really D. flagellare, that species 

 cannot be considered to have been hitherto discovered in Britain. 



The specimens from which the present figures are taken were 

 found in Abbey and Bostol Woods in N. Kent, and were growing 

 on the decaying stumps of Castavea vesca, which is very abundant 

 in that locality. In the same wood, but generally on taller and 

 less decayed stumps, Dicranum montanwn also occurs, and is 

 readily distinguished in the dry state from D. flagellare by being as 

 much crisped as Weissia cirrhata. 



