68 DICRANACp/E. 



1. Ceratodon purpureus Brid. (Mm'um purpureum L.) 

 (Tab. XIII. M.). 



In wide patches, of various tints of green, often accompanied 

 by a tinge of vinous red. Stems branched, §-3 inches long, 

 slender, erect. Leaves erecto-patent, rather laxly imbricated, 

 slightly twisted and appressed when dry, from broadly triangular, 

 ovate to narrow linear-lanceolate, concave, margin revolute from 

 base upwards, becoming plane just below the apex, where there 

 are usually a few coarse teeth ; nerve reaching apex or very 

 slightly excurrent ; cells at base pellucid (in the longer leaves), 

 rectangular, 3-5 times as long as broad, above regularly quadrate, 

 hexagonal-quadrate, or irregular, but always short, small, 

 chlorophyllose. Perichaetial bracts longer, sheathing. Capsule 

 on a purple or sometimes yellowish shining seta, inclined, oblong 

 (when dry and empty oblong-cylindrical), straight or slightly 

 curved, purplish or reddish brown ; when dry cernuous or 

 horizontal, sulcate, 4-5 angled, with a small but distinct struma 

 at base ; annulus large, lid acutely conical, slightly curved. 

 Peristome teeth deep red at base, with equal divisions, bordered 

 on each side from base to middle by the wider inner layer of 

 plates. Dioicous. Male plants more slender, flowers gemmi- 

 form. 



Hab. Sandy and peaty soil, banks in woods, etc. ; very abundant, and cosmo- 

 . politan. Fr. spring and early summer. 



One of the most abundant and polymorphous of our mosses, easily known when 

 in fruit by the narrow, inclined, sulcate, strumose capsule with conical lid. There is a 

 peculiar fades of the leaves when viewed under the microscope, which, allowing for 

 a certain amount of variation in form and size of both leaf and areolation, is directly 

 recognised after a little practice ; the margin recurved to just below the apex, then 

 plane and toothed, is one of the most distinct and constant features ; when moist the 

 leaves usually have a shiny appearance, and the comal ones are generally slightly 

 twisted ; this taken in conjunction with their channelled surface and gradually acute 

 outline, will serve for identification in the field, and an acquaintance with their appear- 

 ance under the lens will save the beginner much labour and disappointment. 



One rather marked form has short, broad, deltoid-oval concave leaves, sometimes 

 shortly cuspidate with the excurrent nerve, the tufts resembling those of Barbula 

 lurida, but with laxer and rather more acute leaves. 



* Ceratodon conicus Lindb. (Trichostomum conicum Hpe.) 

 (Tab. XIII. N.). 



The typical, or extreme form of this plant differs from C. 

 purpureus in the following points. Stems shorter, usually 

 yellowish green ; leaves small, short, ovate-lanceolate, the upper 

 erecto-patent, crowded into a coma, less twisted when dry, the 



