PTEROGONIUM. 



41 



This elegant moss differs from the remaining British Ptero- 

 gonia by the stems being very much branched, and in these 

 as well as the leaves curling remarkably when dry; the fruit 

 too, which isveryscarce, isnearlysessile; the fruitstalk slightly- 

 curved. 



Pt. gracile; branches fascicled, curved ; leaves broadly ovate, 

 acute, concave, their margins plane, summits serrated, faintly 

 two-nerved at the base; lid conical. (TAB. XIV.) 



Ft. gracile. Swartz Afusc. Suec. p. 26. Engl Bot. t. 1085. Pterigy, 

 nandrum gracile. Hedw. St. Cr. v. 4. t. 6. Grimraia ornithopodioidea. 

 Mohr.- Hypnum gracile. Linn. 



HAB. Rocks in sub-alpine countries. 



Miss Hutchins found a variety of this species with the 

 leaves unusually broad, and the whole plant of a blackish 

 green colour. A careful examination of good specimens of 

 the fruit of this plant will exhibit something of an inner pe- 

 ristome, viz. a very narrow membrane as at the base of the 

 cilia of Neckera, yet terminating so irregularly as not to 

 justify us in placing this among the mosses which have a 

 double peristome. 



Pt.Jiliforme; stems irregularly branched, curved; leaves ovate, 

 sub- acuminated, concave, their margins recurved, serrated, 

 nerve single or forked, short, faint ; lid conical. (TAB. XIV.) 



Pt. filiforme. Hedw. St. Cr. v. 4. t. 7. Engl. Bot. t. 2297 . Moug. et 

 Nestl n. 210. Pt. caespitosum. Engl. Bot. .2526. Grimmia filiformis. 

 Mohr. Hypnum cylindricum. Dicks. Smith Fl. Brit. 



HAB. Mountains in Scotland and Ireland ; very rare. 



In this and the preceding species the leaves are closely 

 imbricated and subsecund, but the present plant is the 

 smaller and more slender of the two. The cellules of the 

 leaves are larger than in Pt. gracile and project on the 

 back and margins, which gives them a papillose appearance 

 as in Hypnum catenvlatum, H.proliferum, and a few others. 

 The nerve of the leaf though sometimes scarcely visible, is 

 at others more evident, single, or forked so as to resemble 

 that of Pt. gracile. We have examined specimens of the 

 Pt. ccespitosum of English Botany, which differ in nothing 

 from Pt. Jiliforme but in being somewhat larger, and in 

 having the branches less attenuate. 



