164 



PHYLUM BRYOPHYTA: 



berline they may grow with other plants or be the 

 only plants. In frigid areas, only lichens appear to 

 equal (perhaps sometimes surpass) their hardiness. 

 Therefore, it might not be surprising that alkalinity 

 or acidity of a substrate often appears most influential 

 in limiting their distribution. In fact, particular 

 mosses and liverworts normally indicate the acid, 

 alkali, or mineral nature of their substrate. 



Perhaps the greatest significance of mosses and, 

 less frequently, liverworts is the regularity of their 

 occurrence as a developmental stage in the formation 

 of stable plant communities. In most areas, a moss 

 community appears between a lichen and an herb 

 community. The mosses normally are on fine but 

 thin rock particles before any soil has formed. 



ORDER ANDREALES (Rock, or Black, Mosses) 



Gnmelophyle: of two phases, protonema and game- 

 tophore; each protonema broadly membranous, 

 each normally forming several gametophores; game- 

 tophore leaves blackish or very dark, but sometimes 

 fading to reddish brown or brown; leaves small, fre- 

 quently crowded, smooth to warty, with or without 

 midribs; leaves typically more rigid (actually stiff) 

 and resistant to heavy rains (and perhaps desiccation) 

 than those of other bryophytes; branches equal- 

 forking or clumped. 



Spnrophyle: dark and small; of capsule and false 

 foot, without a distinct stalk; mature capsule opening 

 by four longitudinal lines. 



Occurrence: minute plants (up to 0.4 in. tall); erect, 

 forming dense tufted or cushion-like clumps; espe- 

 cially on granitic or slaty rocks (not on calcareous 

 rocks) of high alpine and subalpine mountain com- 

 munities and lower frigid areas; about 100 species. 



ORDER SPHAGNAiES (Peai Mosses) 



Cametnphyte: of two phases, protonema and game- 

 tophore; protonema broadly thallose, each forming a 

 single gametophore; gametophore leaves whitish or 

 light green but sometimes reddish tinged or yellowish 

 to reddish brown, size variable, frequently crowded, 

 without midribs, water-storing cells present, and 

 every fourth leaf usually below a group of branches; 

 some branches drooping, others erect; mature game- 



tophore without attachment hairs of any kind; re- 

 productive organs resemble those of some leafy 

 liverworts. 



Spnrophyle: dark and small; of capsule and false 

 foot, without a distinct stalk; mature capsule opening 

 by a lid. 



Occurrence: plants up to 7 feet long, generally 

 intertangled with one another, often packed into 

 dense masses that will support humans; common in 

 moist to aquatic situations that lack calcium, in cool 

 temperate to arctic climates, especially common in 

 glacially formed lakes; about 300 species. 



ORDER BRYALES (Mosses) 



Gametophyte: of two phases, protonema and game- 

 tophore; protonema mostly filamentous, rarely 

 broadly membranous; gametophore leaves yellow- 

 green, green, dark green, or blackish, size variable, 

 crowded to open, with or without a narrow or broad 

 midrib; branching variable but not arranged in close 

 groups. 



Sporophyte: often greenish and larger than other 

 Musci; of capsule, foot, and stalk; mature capsule 

 usually opening by a lid, or opening irregularly. 



Occurrence: mostly a few inches tall, minute to 

 about 24 inches; erect, prostrate, or ascending; widely 

 distributed from dry to aquatic situations, mostly in 

 moderately moist situations; about 14,000 species. 



SEtECTED READINGS 



Bodenberg, E. T., 1954. Mosses: A Neiv Approach to the 

 Identification of Common Species. Burgess Publ. Co., 

 Minneapolis, Minn. 



Campbell, D. H., 1918. Structure and Development of Mosses 

 and Ferns. The Macmillan Co., New York. 



Conard, H. S., 1944. How to Know the Mosses. Wm. C. 

 Brown Co., Dubuque, Iowa. 



Frye, T. C, and L. Clark, 1937-1947. Hepaticae of .\orth 

 America. University of Washington Press, Seattle, 

 Wash. 



Grout, A. J., ed., 1928-1934. .Moss Flora of .\orth .America. 

 Publ. by the editor. 



Grout, A. J., 1947. .Mosses with a Hand Uns. 4th ed. Publ. by 

 the author. 



Palmer, E. L., 1949. Fie Idbook of .\atural History. McGraw- 

 Hill Book Co., New York. 



