MAN^UAL 



OF 



NOETH AMEHICAN MOSSES. 



Ordek I. SPHAGXACE.E. Peat Mosses. 



Soft and flaccid caulescent Mosses, generally of large size, 

 growing in more or less compact tufts or patches on the surface 

 of bogs, or floating in stagnant water, more rarely on the bor- 

 ders of mountain rivulets, whitish, yellowish, sometimes red 

 or olive-colored, perennial by the annual prolongation of the 

 stems or by simple innovations at the apex. Stems mostly un- 

 divided and bearing copious lateral branches, composed of a 

 triple cellular tissue, the outer (cortex) of large loose cells, the 

 intermediate woody, the central parenchymatose or medullary. 

 Branches partly spreading, partly deflexed and appressed to the 

 stem, in lateral fascicles of 2 to 7, rarely more, those at the 

 summit of the stem capitate, the fascicles gradually more dis- 

 tant downward. Leaves nerveless, translucent, formed of a 

 single layer of two kinds of cells ; 1st, large colorless and hya- 

 line ones (utricles), generally perforated by pores and lined 

 with sjjiral or circular filaments {fibrils), hence fibrillose and 

 porose ; 2d, smaller chloroi^hyllose ones (ducts), narrowly linear, 

 continuous, forming a net of rhomboidal or hexagonal meshes 

 around the utricles : stem-leaves distant, obliquely inserted, 

 erect or deflexed, flat or concave, ovate, obovate, or linguiform, 

 generally obtuse, loosely areolate, their utricles often destitute 

 of fibrils and of pores ; branch-leaves smaller, imbricated and 



