THE SPRING FLOWERS OF COLORADO. 67 
birds of bolder wing construct their homes securely, and from 
many a dark recess the melancholy owl pours forth her plaintive 
wailings upon the ear of night. Yet these mighty barriers are 
not altogether impassable. Among the irregularities of their out- 
line are places where little streams bordered with shrubs and bushes 
-come singing down among the rocks, from the table land. Even 
broad and easy passage ways may be sought out by the eye before 
commencing the ascent. 
These table lands, when reached, are usually found to present 
an uneven surface of bare rock, or, in places, of shallow soil. 
There are even extensive meadows on some of them with occasion- 
ally a pond of water. In sheltered situations opening toward the 
south where the spring sun first drove away the snow, there are al- 
ready some real treasures for the botanist’s portfolio. In every 
crevice and hollow, where there is a little soil, we find a very 
handsome cruciferous plant which has yet no name by which to be 
known, save the Latinized Greek one, Physaria didymocarpa. Its 
pretty rosettes of broad whitish leaves, which lay all winter close 
to the frosty rock, have now sent up a number of spreading stems 
with golden yellow flowers. A small variety of Thermopsis faba- 
cea, with fragrant lupine-like blossoms, will be found where the 
soil is deeper, but the larger and more common form of this plant 
flowers a month later, on the plains below. 
The most interesting tenant of these heights is the Echinocactus 
Simpsonii. As its name would indicate, it belongs to the cactus 
tribe. It is remarkable among the cactaceous plants of this lati- 
tude for its early flowering. Not less than a dozen species or va- 
rieties of these plants, grow upon the adjacent plains, but none of 
them are in flower before the first of June. This one may be 
found in perfection before the last of April. It is globose in form 
and very thickly armed with whitish spines, so that, when out of 
flower, the plants seem like mere balls of bristles scattered about 
among the rocks. The flowers are five or six in number, of a 
bright purple, forming a circle around the centre, or rather, apex 
of the plant. It is an object of very singular beauty, alone well 
worth the trouble and fatigue of an hour’s climbing. 
As the first of May draws nigh, the general aspect of the coun- 
try becomes more springlike. The grasses are beginning to grow, 
and the number of flowers begins to increase so that to enumerate 
them would be tedious. However, we must not fail to notice a 
