104 ANNALS OF SCOTTISH NATURAL HISTORY 



NEW AND RARE SCOTTISH MOSSES. 

 By Dr. JAMES STIRTON, F.L.S. 



PLAGIOTHECIUM KINLAYANUM (Strn.} The following is a 

 rather more detailed description than that published in 1874: 



In close yet indeterminate patches of a green or yellowish-green 

 colour, or straggling over other mosses ; stems mostly procumbent, 

 yellow then reddish, sparingly and irregularly branched, upper 

 branches often the longest, producing stolons also from the upper 

 part, having scattered, minute, slender, pointed leaves ; leaves 

 proper laxly disposed around the stem and slightly complanate, very 

 concave, symmetrical, nearly elliptical, with a longish apiculus at 

 the extremity, margin recurved from base up to and including 

 apiculus ; breadth of reflexed portion near the middle of leaf as 

 much as '035 mm., composed of narrower cells, about '08 by 

 oo8-'oii mm.; containing frequently crowds of minute, well- 

 defined, oval cells, much resembling the minuter stereids ; leaves 

 decurrent, this portion composed of bluntly quadrate, hyaline cells, 

 '35''5 by '025-'o35 mm., in two to four perpendicular rows; cells 

 near base oblong, very large, 'oS-'n by - oi8-'o24 mm., upwards 

 more rhomboid, 'o6-'o85 by > oi5-'o2 mm. ; nerve broad at base 

 and thickish, single in the lower third, then generally splitting into 

 two unequal branches which proceed upwards for nearly another 

 third of the leaf; primordial utricles seen almost constantly in cells 

 for the upper two-thirds. 



Unlike any other Plagiothecium, especially when seen in a moist 

 state, inasmuch as the leaves are then hollow and appear scarcely 

 complanate, yet allied to PI. sylvaticum in the shrinking of the dried 

 leaves owing to the very large cells, larger probably than those of 

 any other member of the genus, and in the presence of stolons, 

 which, however, are usually emitted from the upper part of the 

 stems, and not from the axillae of the branches or leaves. As the 

 longish apiculus to the leaf is dragged back by the uppermost part 

 of the recurved margin, it, too, is recurved, and not unfrequently 

 appears quite uncinate. Barren. 



The best way to ascertain the nature of the recurved margin is 

 to view from behind a thoroughly moistened leaf by means of a 

 lens, when there is seen, all round and just within the margin, a 

 groove, or rather furrow. If this leaf is slightly pressed between 

 two slips of glass and viewed through the microscope, the reflexed 

 margin is seen all round, including the apex ; if, however, too much 

 pressure is used, the concave leaf is split in the upper part, and the 

 reflexed margin is undone and appears plane to a corresponding 

 extent. Ben Wyvis, Ross-shire, A. M'Kinlay, 1867 ; Ben Sleoch, 

 Loch Maree, Stirton, 1870. 



