1 82 UNIVERSITY OF COLORADO STUDIES 



knife is hardly strong enough to cut the twigs. On dry slopes, exposed 

 to wind, this plant puts forth great numbers of small, short branches, 

 thus producing a dense, scrubby growth. Although the flowers of 

 the mountain mahogany are small and inconspicuous, the fruits are 

 interesting because of the long tail-like style which grows to a length 

 of two or three inches. 



The nine-bark^ and wax-flower* are shrubs which produce con- 

 spicuous flowers. It is mostly in rocky-places that these are to be 

 found — seldom on open slopes. Lower down in the foothills these 

 plants occur only in the more shaded situations, as along canyon- 

 walls and in deep gulches. Although the rainfall at Florissant is not 

 much greater than at lower altitudes, yet the smaller amount of evap- 

 oration permits plants to grow in more open situations. 



Trees are nowhere abundant in the lake basin at Florissant, but 

 there are some good stands of spruce in the higher hills a few miles 

 away. All the lower ridges have a few trees. Most of these are pines^ 

 and spruces, with here and there a cedar. Low mats of juniper are 

 scattered about, chiefly on the steeper slopes. Aspens may be found 

 in soil somewhat more moist than that which supports the cone- 

 bearing trees. A number of dead aspens of some size are to be seen, 

 but none of the living specimens are at all large. A few years ago 

 there was an invasion of caterpillars. It is stated that the aspen trees, 

 during that year, were again and again stripped of leaves. This caused 

 the death of the trees. "* 



In the aspen groves may usually be found certain species of herba- 

 ceous plants not so abundant among the pines and spruces. This 



' Opulaster. ' Edwinia, or Jamesia. 



3 Shown in the photographs reproduced in the plate at the end of this article. 



< Following is a list of woody plants obtained by the writer. On account of the short time which he 

 was able to give to the collection of plant specimens at the time of his visit to Florissant, the list is by no means 

 complete. However it will give an idea of the more common or striking species. 



Arctoslaphylos uva-ursi (Linn.) Spreng. Pinus scopulorum (Englem.) Lemmon 



Beluia fontinalis Sarg. Populus tremuloides Michx. 



Cercocarpus parvifolius Nutt. Prunus demissa melanocarpa Aven Nelson 



Dasiphora fruticosa (Linn.) Rydb. Pseudotsuga taxijolia (Poir) Britt. 



Edwinia americana (T. & G.) Heller Ribes cereum Dougl.- 



Juniperus sibirica Burgsdorff Rubus deliciosus James ^^ 



Opidaster intermedins Rydb. Salix stricta (And.) Rydb. 



Pinus murrayana "Oreg. Com." 



These determinations were aU made by Professor Aven Nelson. 



