EUROPE AND NORTH AMERICA. 



31 



MONOGRAPH OF THE SPECIES FOUND IN 

 EUROPE AND NORTH AMERICA. 



SPHAGNUM, DiLLEN. 



Stems dichotomous, fastiglate, erect, renewed by an annual in- 

 novation at apex ; ramuli fascicled at base, flagelliform, partly 

 patulous, partly adpresso-reflexed ; the younger clavate, erect, 

 clustered in a dense capitulum at summit of stem. Cauline leaves 

 5-ranked, erecto - incumbent or reflexed, soft; ramuline leaves 

 imbricated, nerveless, pale and fragile when dry ; the areolation 

 composed of large vesicular, sigmoid, hyaline cells, containing 

 spiral fibres and perforated by pores, and separated by narrow 

 duct-like opake cells placed between their adjacent walls. In- 

 florescence monoicous or dioicous ; the male strobiliform on lateral 

 ramuli, antheridia very numerous, solitary at the side of each 

 involucral bract, pedicellate, subglobose ; female forming long 

 gemmules with 1-5 archegonia, and branched, thread-like para- 

 physes. Fruit solitary, concealed in the perichaetium, and at matu- 

 rity elevated on an elongated pseudopodium. Capsule globose, 

 sessile on the top of the^ vaginula, brown ; operculum minute, 

 hemispherical, without annulus or peristome ; columella elevated, 

 hemispheric, covered by the excavato-hemispheric sporangium , 

 pericarpic membrane very thin, whitish, torn irregularly, adhering 

 partly to the capsule, partly to the top of the vaginula. 



Plants dwelling in marshes and peat bogs, aggregated in dense 

 tufts or cushions, which consist all of one species or of an ad- 

 mixture of two or more ; absorbing water with great avidity and 

 retaining it like a sponge. 



Sect. I. — EusPHAGNUM, Lindb. 



Plants pale green, whitish, or ochraceous, occasionally more or 

 less tinged with purple. Branches of two forms, in distinct fascicles 

 of 3-12, part divergent or decurved, part attenuated, slender, and 

 pendulous. Branch leaves imbricated, ovate or ovato-lanceolate, 

 the cells rhomboidal, curved, containing fibres, and with marginal 

 pores. Perichaitial bracts much larger, broad, and convolute. 

 Capsule exserted, globose, with a shallow, convex lid. 



