VOL. 111.] The Flora of Sonora. 347 
its bright yellow flowers and winged seeds flourish amongst the sur- 
rounding dried-out vegetation. 
The most interesting part of Sonora visited was Las Durasnillas, 
a small collection of houses about sixty miles from Hermosillo, near 
a mountain range known as Sierra Matapan. At this place was found 
a flora very different from any before seen, and some moist localities 
along the base of the mountain had retained their green and grow- 
ing vegetation longer than was to have been expected. The most 
conspicuous plant was Cesalpinia pulcherrima, with its large and 
handsome blossoms, compelling admiration from the least attentive. 
The very dark-purple flowered Brongniartia Palmeri was equally 
abundant. Some of the Pithecolobiums were in bloom, and under 
one of them our camp was made, as they furnished more shade than 
any other tree of the region, but a denser shade would have been 
more agreeable, because the hot sun found many openings among 
the scattered leaves and branches through which to send its rays. 
Among the trees and shrubs some are so different from familiar forms 
that they areaconstant source of interest, and even the inhabitants rec- 
ognized their peculiarities, and, after exciting our curiosity, guided us to 
the places where they grew. The cotton tree, Eviodendron acumin- 
atum, is a singular trée, having the bark of its trunk thickly covered 
with large thorns, with leaves like those of the buckeye or horsechest- 
_ nut, and large yellow flowers that are followed by bolls of cotton four 
or five inches long. When the fruit bursts and the tips of the twigs 
and branches of a spreading tree twenty feet high are adorned with 
good-sized bunches of cotton, the effect is very striking. Another 
tree, with a trunk sometimes two feet in diameter, that is always 
nearly white, and for that reason called ‘‘ Palo blanco,’’ surprises 
even botanists when they observe its botanical relationship, for it is 
an Ipomoea, a genus seen in more temperate climates only as low 
twining herbaceous plants. Among so many interesting plants, a 
few others are deserving of notice. Erythrina is represented by a 
‘single species here, and in Lower California by another very distinct 
one; both blossom in the spring, some time before the appearance of 
the leaves, and both retain their long pods after the short-lived foliage 
has fallen. The abundant large, dark maroon colored flowers 
are as beautiful in April as are the open pods that expose their scarlet 
beans in December. Cordia Sonore is completely covered with 
flowers that persist on the bushes and assume different shades of 
