HOW TO KNOW THE FRESH-WATER ALGAE 



308a Cell membrane in 2 sections, the upper lifting off at maturity to 

 allow escape of aplanospores (small globular spores); cells oval 

 or short-cylindric. Fig. 215 CHLOROTHECIUM 



Fig. 215. Chlorothecium Pirottae Borzi. 



This cylindrical plant with parietal yellow-green 

 chromatophores is attached by a short stalk and a disc 

 to submerged plants, including larger algae. It is 

 rather rare (only one species reported from this coun- 

 try) and is easily overlooked because it occurs in the 

 dense mixture of algae from bogs. 



Figure 215 



308b Cell membrane not in 2 sections 309 



309a Cells globose or subglobose; cytoplasm reticulate. Fig. 216.... 



PERONE 



v 



H, 



Fig. 216. Perone dimorpha Pasch- 

 er. a, rhizoidal stage; b, vege- 

 tative cell. 



'.'V 



A r r i 



/#^°5 



c 



a j.^- : — •* 



There is a freely moving amoe- 

 boid stage and an attached or en- 

 dophytic encysted stage in the life 

 history of this plant. In the resting 

 stage the cell is to be found in 

 Sphagnum or other moss leaves, 

 Figure 216 with a highly recticulated, faintly 



pigmented protoplast. 

 309b Cells shaped otherwise; cytoplasm not highly recticulated nor 

 alveolar. Fig. 217 CHARACIOPSIS 



Fig. 217. a, Chaiaciopsis acuta 

 (Braun) Borzi; b, C. cylindiica 

 (Lambert) Lemm.; c, C. spinifer 

 Printz. 



There are several fairly common 

 species of this genus which occur 

 as epiphytes on filamentous algae. 

 They vary in shape and in length 

 of attaching stalk. Unlike the 

 genus Characium (Fig. 87), some 

 species of which are very similar 

 in shape, no starch is formed and 



The starch-iodide 



the 



Figure 217 



chromatophore is pale green or yellowish-green 



133 



