186 Plant Biology 



10. Bryophytes, including mosses and liverworts, possess chlorophyll in 

 chloroplasts for the purpose of photosynthesis. 



11. Mosses and liverworts possess similar methods of reproduction and 

 life cycles and are much alike structurally and functionally in spite of 

 diflferences which may be apparent upon casual observation. 



12. True mosses belong to the subkingdom Emhryophyta, the phylum 

 Bryophyta, and the class Musci (mus' si) (L. muscus, moss). 



13. Liverworts belong to the subkingdom Emhryophyta, the phylum 

 Bryophyta, and the class Hepaticae (he-pat'ise) (L. hepaticus, liver). 



TRUE MOSSES 



1. Polytrichum (po -lit' ri kum) (Gr. polys, many; thrix, hair) is a 

 common, true moss known as the hairy cap moss. Mosses are small 

 terrestrial plants which require a certain amount of moisture for growth 

 and fertilization processes. They usually grow so densely as to form a 

 mass of vegetation. Each individual plant consists of a stemlike axis to 

 which are attached small, leaf like appendages (not true stems or leaves 

 because of the absence of the vascular tissues, phloem and xylem) (Fig. 

 45). Rootlike rhizoids absorb materials and anchor the plants. 



Several male antheridia (an the -rid' i a) (Gr. anthos, flower; idion, 

 diminutive) are borne in a cluster at the tips of certain stemlike axes, 

 while several female archegonia (ar ke -go' ni a) (Gr. arche, beginning; 

 gonos, offspring) are borne at the tips of other stemlike axes. Poly- 

 trichum has its sexes in separate plants, being diecious (di -e' si us) (Gr. 

 dis, two; oikos, house). In other species of mosses the antheridia and 

 archegonia are borne on the same plant, being monecious (bisexual). 



In Polytrichum the antheridia are separated by multicellular, sterile 

 hairs called paraphyses (pa -raf i sez) (Gr. para, beside; physis, growth), 

 and both are surrounded by a rosette of leaflike appendages which may 

 be colored and resemble a "flower." Each antheridium consists of a 

 short stalk and an enlargement which produces unicellular male sperms. 

 The sperms are coiled, bear two long, terminal flagella, and escape from 

 the apex of the antheridium. 



The female archegonia are separated by paraphyses, and each arche- 

 gonium has a stalk supporting an enlarged venter which surrounds the 

 egg. When mature, a canal leads through the long neck to the venter. 

 During fertilization the motile sperm swims through water from the 

 antheridium to the female plant. It travels down the canal to the 

 venter where a sperm and &gg fuse by the fertilization process known as 



I 



