152 UNIVERSITY OF COLORADO STUDIES 



Plants of Forest Zone — Continued 

 Potentilla concinna Chrysopsis foliosa 



Potentilla dissecta Machaer anther a varians 



Rosa sayi Senecio mutabilis 



Sibbaldia procumbens Senecio perplexa 



*Aragalhis lamberti Senecio purshianus 



Aragallus multiceps Solidago decumbens minuescens 



* Aragallus multiceps minor Tetraneuris lanata 



* Astragalus sulphurescens Crepis perplexa 

 * Abundant and conspicuous species. 



Lake Zone 



The designation "lake zone" is used for convenience to make it 

 correspond with the names of the shore formations. With so few 

 species present it seems not desirable to separate floating, submersed 

 and half-submersed zones. 



The water lilies (Nymphaea polysepala) are the most prominent of 

 the water plants. They form dense growths, especially at the western 

 part of the lake where there is a soft mud bottom. There are also large 

 floating "islands" of the leaves scattered about through the lake. It is 

 not until mid- June that the lily pads become conspicuous. By July 1 

 a number of the plants are in bloom. From that time until the middle 

 of August flowers are to be found in some part of the lake. Water 

 lilies undoubtedly play an important part in the ultimate filling up of 

 such lakes as the one under discussion. 



Bur reed (Sparganium angusti folium) forms in places a distinct zone 

 in water about 5 dm. (1 . 5 feet) deep. The long narrow leaves float 

 on the surface in a close formation. The writers noticed in some of 

 Stapp's lakes about three miles (5 km.) north of Redrock Lake an 

 uninterrupted zone of Sparganium between the water lilies and the 

 sedges of the shore. Professor Clements has noticed in certain lakes of 

 the Pike's Peak region a complete filling up with this plant. This 

 condition is recorded for Michigan Lake by Shantz. 1 



The only submersed species recognized by the writers are Potamogeton 

 alpinus, Zannichellia palustris and Batrachium flaccidum. It is inter- 

 esting to note the absence from this lake of Myriophyllum, Polygonum 



1 Shantz, "Biological Study of the Lakes of the Pike's Peak Region," Trans. Amer. Mic. Soc, 

 Vol. XXV, p. 85, 1907- 



