vor,. III.] 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 Herniosillo, 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 Cccsalpinia ptdcherrima, 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 tr^es and shrubs some are so different from familiar forms 

 that theyareaconstantsourceof 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, Eriodcndron aciimin- 

 ahim, is a singular tree, 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 bianco," surprises 

 even botanists when they ob.serve its botanical relationship, for it is 

 an Ipomcea, 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 scarle^ 

 beans in December. Cordia Sonor(s is completely covered with 

 flowers that persist on the bushes and assume different shades of 



