480 ELEMENTARY BIOLOGY 



Below the archegonium plants are all those that lack special- 

 ized vegetative organs. Here are included all the seaweeds, the 

 bacteria, and the fungi. 



503. The main groups of plants. The chief groups of plants 

 are indicated in the following outline : 



DIVISION I THALLOPHYTES. Plants showing little or no differentiation 

 into stem and leaf. 



A. Schizophytes ("splitting plants"). Each cell splits into two ; no other 



reproduction. 



1. Cyanophyceae. Splitting plants with chlorophyl, the blue algae. 



(Examples. Oscillatoria, Rivularia, Nostoc.) 



2. Schizomycetes. Splitting plants without chlorophyl. This group 



includes all the bacteria. 



The distinction between having chlorophyl and not having chlorophyl sep- 

 arates all the thallophytes into two main groups, the algae and the fungi. 



B. Algae. The chlorophyl-bearing thallophytes. 



1. The green algae. Usually yellowish green. (Examples. Pleu- 



rococcus, desmids, Spirogyra, Vaucheria, stonewort, sea 

 lettuce.) 



2. The brown algae. (Examples. Bladder wrack, Laminaria, Sar- 



gassum, diatoms, sea palm.) 



3. The red algae. Mostly marine ; reddish to purple. (Examples. 



Nemalion, Polysiphonia, Batrachospermum.) 



C. Fungi. Thallophytes without chlorophyl. 



1. Phycomycetes. Alga-like fungi. (Examples. Water molds [often 



parasitic on fishes], phytophthora [the cause of the potato rot], 

 grape mildew and other parasitic forms, black mold.) 



2. Ascomycetes. Fungi bearing spores in sacs. (Examples. Yeast, 



cup fungi, the edible morel, the mildews, black knot.) 



3. Basidiomycetes. Fungi bearing spores on outside of structure 



called basidium. (Examples. Rusts, smuts, mushrooms, pore 

 fungi, shelf fungus, puffballs.) 



D. Lichens. These curious structures are compound growths of fungi 



and algae. The hyphae in these partnerships generally belong 

 to ascomycetes; the algal partner is a green alga related to 

 pleurococcus or one of the blue-green algae. (Examples. Rein- 

 deer moss, Iceland moss, Spanish moss. The common names 

 introduce the word moss, although these plants are in no way 

 related to the mosses.) 



