TORTULACE^.] 279 [Leersia. 



In Mr. Hunt's herbarium is a specimen of C. aquations, with the label 

 " Mourne mountains, Co. Down, Ireland, with C. fontinaloides," but as no 

 recent collectors have met with it, I have not figured it, although it is a 

 species quite likely to occur ; it may be readily distinguished by the leaves, 

 which are narrowly linear-lanceolate and falcato-secund. 



Subf. 3. LEERSIE^E. Plants growing in small tufts on the ground or 

 on rocks. Leaves spathulate, basal cells fragile, hyaline, foraminate, upper 

 with verruciform papillae. Calyptra large, cylindric, rostrate. Capsule 

 cylindric ; peristome none, single or double. 



LEERSIA Hedw. 



Fund. muse. II, 88 (1782). 



Plants caespitulose, dichotomous. Leaves lingulate or spathulate, 

 the basal cells rectang. fragile, hyaline, foraminate, the upper chloro- 

 phyllose, papillose. Calyptra enclosing the whole caps., cylindric with 

 a styliform beak ; caps, cylindraceous, erect on a tall seta ; per. none, 

 simple of 16 teeth or double. Inhabiting the ground and rocks. 

 Named in honour of John Daniel Leers of Herborn in Nassau. 



The fine mosses which constitute this genus are readily known by their 

 large tubular calyptra, which is very persistent, and in falling takes the lid 

 with it. The large opake leaves are not unlike those of Tortula subulata, &c., 

 but are generally rufous at base, and their upper cells are protuberant and 

 provided with large papillae, cleft at top into several heads. The vaginula is 

 oblong and generally crowned with an ochrea or saucer-shaped membrane 

 originating in the base of the calyptra, which in the young state is inflexed, 

 and when older and torn off, is entire, or lacerate, or fringed with ramentaceous 

 processes. The peristome when present consists of red, slender teeth 

 composed of 14 series of cells, and the endostome of pairs of cilia, concrete 

 above, joined at base to a thin punctulate membrane adherent at the 

 lower part to the teeth of the peristome. 



Schreber in 1791 superseded Hedwig's name by that of Encalypta and 

 Leersia was again used in 1788 by Swartz adopting a MSS. name of 

 Solander's for a genus of grasses which had already in 1776 been named 

 Homalocenchrus by Mieg in Pollich*'s Hist. Plant, in Palatinatu ; it is clear 

 therefore that the original name Leersia must be retained for the genus of 

 mosses. About 25 species are described. 



CLAVIS TO THE SPECIES. 



Capsule smooth or faintly striolate. 



Calyptra not fringed at mouth, peristome none. 



Calyptra smooth at apex. alpina. 



scabrous at apex. exstinctoria. 



Calyptra fringed at mouth, peristome present. laciniata. 



Capsule sulcato-striate. 



Plants short ; strias vertical. rhabdocarpa. 



tall ; striae twisted spirally. contorta. 



Sect. i. PSILOTHECA C. Muell. Capsule smooth or faintly striolate. 



