fil 



HUYACEiE. 



[ACROGENS. 



Order XX. BRYACEiE.— Urnmosses. 

 , r /-. in l-Toni DUuinikM *< Adumb (1787-1797); Bridel Musenloq. rcccntiomm 



FPern. 



Grey. 



459. 



830). Brjraceie, Etf. //r. (1836) ;"£mK. to. xxiv. Sphagnaceae, £«cW. Gera.xxiii. 



Diagnosis.— Spore-cases valveless, icltlt an operculum, without elaters. 



Erect or creeping, terrestrial or aquatic, cellular plants, having a distinct axis of 



Erowth, destitute of a vascular system, and covered with minute imbricated, entire, or 



serrated leaves. Reproductive organs of two kinds, viz. 1. Antheridia winch are axillary, 



cylindrical or fusiform 

 stalked sacs, containing 

 a multitude of spherical 

 or oval particles emitted 

 \ ^J U W upon the application of 



U 0(1 i 1 ^ 11 ~ water, and coiled up 



bodies which move in 

 water with activity ; 2 

 Pistillidia, or flask-like 

 bodies inclosed within a 

 convolute bract, which is 

 eventually carried up up- 

 on the point of the spore- 

 case. Spore-cases, or 

 ripened pistillidia, hollow 

 urnlike vessels, seated up- 

 on a seta or stalk, covered 

 by a membranous calyp- 

 tra, closed byalid oroper- 

 culum, beneath which are 

 one or more rows of cel- 

 lular rigid processes, call- 

 ed collectively the peri- 

 stome, and separately 

 teeth, which are always 

 some multiple of four, 

 and combined in various degrees ; the centre of the theca is occupied by an axis or colu- 

 mella, and the Space between it and the sides of the theca is filled with sporules. Spo- 

 rulea in germination protruding confervoid filaments, which afterwards ramify, and 

 form -in axis of growth at the point of the ramifications. 



These little plants, which form one of the most interesting departments of Crypto- 

 gamic Botany, are distinctly separated from all the previous tribes by the peculiar 

 structure of their reproductive organs, in which they resemble no others, except the 

 Sealemosses, whose approach, however, is more apparent than real. In their organs 

 of vegetation they are strikingly similar to many Clubmosses, to which, perhaps, an 

 approach is made by Sphagnum, whose spore-case has no peristome, on which account, 

 indeed, that genus is regarded as a distinct Natural Order by Endlicher. 



For a long time Urnmosses were considered to be destitute of stomates ; but first 

 Treviranus, and afterwards Valentine, distinctly proved those organs to be present ;(Ztom. 

 Trans. 1)1, 289). In addition to such apertures, some of the cells of certain species of 

 Sphagnum are pureed with large round openings ; and Rceper has observed, that such 

 perforated cells are the habitation of the animalcule called Rotifer vulgaris. {Flora, 

 1838, p. 17.) Mold has observed similar openings in the cells of Leucobryum vulgare, 

 (Dicranum glaucum,) and Octoblepharum albidum ; he thinks they are formed subse- 

 mieutly to the construction of the c ells. Ann. Sc. N. s. xiii. 108. Schleiden confirms 



Pig. XLV. -1. IVristoroe of Tort.ib ruralis ; 2. Theca of Ceratodon purpureus ; 3. Supposed repre- 



ShSwf? ,'• * S ° X " : , ° rKa "^ '," ML ' ,si '' u, "~ i ^ t:l i 4 - Bryum roseuin ; 5. Peristome of Octoblepharuin 

 albmmu ; B. Apophysis and theca of Splachniim luteuiu. 



G 

 Fig. XLV. 



