TAXONOMY 
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Order 1. — Sphagnales, or Bog Mosses, including the simple genus, 
Sphagnum. Pale mosses of swampy habit whose upper extremities 
Fig. 109. — Sphagnum aculifolium, Ehrb. A, prothallus (pr), with a young leafy 
branch just developing from it; B, portion of a leafy plant; a , male cones; ch, 
female branches; C, male branch or cone, enlarged with a portion of the vegetative 
branch adhering to its base; D, the same, with a portion of the leaves removed so 
as to disclose the antheridia; E, antheridium discharging spores; F, a single sperm; 
G, longitudinal section of a female branch, showing the archegonia (ar); H, 
longitudinal section through a sporogonium; sg 1 , the foot; ps, pseudopodium; c, 
calyptra; sg, sporogonium, with dome of sporogenous tissue; ar, old neck of the 
archegonium; J. Sphagnum squarrosum Pers.; d, operculum; c, remains of calyp- 
tra; qs, mature pseudopodium; ch, perichaetium. (Gager, from Schimper.) 
repeat their growth periodically while their lower portions die away 
gradually and form peat, hence their frequent name of Peat Mosses. 
