TRUE MOSS 



Bryophyta 



Many submersed aquatic plants are commonly referred to as moss, 

 which is botanically incorrect and leads to confusion in obtaining 

 information on control measures. Mosses or Musci {txwt mosses) 

 belong to the plant division BryophytasLud are a higher type plant than 

 filamentous green algae with which they are often confused. 



The conspicuous plant, or gametophyte, of commonly observed 

 mosses is differentiated into an erect central axis or stem with small 

 spirally arranged leaves resembling those of true flowering plants. True 

 mosses do not have roots, but are anchored to the substratum by 

 threadlike projections, or rhizoids, that fan out from the base of the 

 stem. 



True mosses are predominantly land plants, being one of the 

 simpler types of green terrestrial plants. A few species are aquatic or 

 semi-aquatic in growth habit and vary in size. Generally, true moss 

 produces short stems only a fraction of an inch in length that arise 

 from dense mats of growth. A few representatives are much larger, 

 producing stems up to 150 to 200 millimeters in length. 



True mosses are occasionally found growing on small areas on canal 

 linings, often in the shaded areas, and where a thin soil substrate is 

 available. They occasionally are reported to cause problems to water 

 distribution systems. Two genera of mosses have been reported in 

 Western irrigation systems, although many others undoubtedly occur. 

 These genera are Fontinalis, which is one of the largest mosses, and 

 Fissidens y a much smaller plant. A typical growth of the moss 

 Fontinalis is shown as it might be found on a lined canal. 



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