DICRANACE^;.] 127 [Campylopus. 



ii. CAMPYLOPUS BRID. 



Mantissa 71 (1819). 



Mosses resembling Dicranum in habit. Leaves with a broad nerve 

 of several strata of cells, furrowed or smooth at back ; basal cells 

 dilated, hyaline or brown at the excavated angles. Calyptra cucullate, 

 fringed at base. Caps, on an arcuate or flexuose or rarely straight seta, 

 equal, pachydermous, generally striated, deeply sulcate when dry. 

 Annulus of i 3 series of cells. Peristome dicranoid. Inhabiting turfy 

 ground and rocks. Der. ra/xTruXos curved, TTOUS a foot. 



Nearly 200 species are referred to this genus, some of which are no 

 doubt synonymous, and a great number are only known in a sterile state ; 

 more than one-third of them are natives of central America. C. Mueller and 

 some other bryologists retain the genus as a section of Dicranum, yet it has 

 a peculiar facies readily recognized after a little practice, by which we may 

 with certainty separate the two. Several species produce slender flagelliform 

 branches, by which they propagate, and very frequently the stems are matted 

 together by an abundance of branched radicles produced from the axils or 

 backs of the leaves. The leaves themselves are densely crowded, imbricated 

 when dry, erecto-patent when moist, and frequently terminate in a white 

 hair ; above the base the marginal cells are extremely narrow, and they 

 become wide and rectangular towards the nerve, the transverse walls being 

 frequently incrassate, in the narrow part of the lamina they are much smaller, 

 quadrate, rhombic or oval, and often crammed with chlorophyl ; the structure 

 of the nerve is best seen in transverse section, the back of it being often 

 furrowed by the projection of alternate rows of cells, which sometimes even 

 extend into lamellae. The curious falling off of the leaves in several species 

 of this genus and in the last is attributed by Lindberg to some change in the 

 contents of the basal cells, akin to the fatty degeneration in animal tissues, 

 the result being the arrest of circulation through those cells and their separa- 

 tion from the stem. 



CLAVIS TO THE SPECIES. 

 Leaves concolorous. 



Leaves not auricled at base. 



Nerve J width of leaf-base. pyriformis. 



Nerve more than J width of leaf-base. 

 Stems tomentose above. 



Nerve width of base ; basal cells large, lax, hyaline. fragllis. 



Nerve f width ; basal cells small and narrow. Schimperi. 



Stems not tomentose above, very short. subitlatus. 



Leaves auricled at base. 



Stems not tomentose above, nerve above half width of base. 

 Leaves dense, nearly entire. 



Leaves shortly and gradually subulate, margin inflexed 



from above base. Schwarzii. 



Leaves longly subulate by the margin being inflexed 



suddenly at \ their length. Shawii. 



Leaves distant, serrate above. setifolius. 



Stems tomentose throughout, nerve one-third width of base. 



Leaves long, suddenly subulate for $ length of leaf. fiexuosus. 



Leaves short, gradually narrowed into a subula half their length, paradoxits. 

 Leaves with hyaline points. 

 Point of leaf a hoary hair. 



Leaves auricled at base ; nerve J width. atrovirens. 



Leaves not auricled ; nerve width. introflexus. 



Hyaline point very short ; nerve j width of base. bravipilus. 



