* % 



abundance. These plants, so common about the lakes, were seen in no 

 other place during our summer's explorations. 



Up the Rio Grande, as far as to fifteen miles above Del Norte, noth- 

 ing of interest was noticed ; there we first meet with Berberis Fendleri, 

 which, after we had crossed the main range, was found quite as plenty 

 upon the western slope. 



Wagonwheel Gap, through which the waters of the Eio Grande have 

 barely room to find their way, is a canon of magnificent beauty, and is 

 very interesting botanically. Although only 8,000 feet above sea-level, 

 Cryptogramme achrosticoides flourishes among the loose rock. On the 

 face of the cliffs and among the debris at their base, a new Gilia, G. 

 Brandegei, Gray, was found growing in abundance. But for its yellow 

 flowers, it would have been passed by as Polemonium confertum, var. 

 mellitum, which it almost exactly imitates in leaves and fragrant vis- 

 cosity. 



At the head of Los Pinos Creek we leave the Bio Grande, cross the 

 Sierra Madre, and come upon the western slope of the Kocky Mountains. 

 The alpine and subalpine floras at this southern latitude are almost 

 exactly the same as those of Northern Colorado. Pachystima Myrsinites 

 and Erytlironium grandiflorum are very common, and Aquilegia Canadensis 

 almost entirely takes the place of A. ccerulea. Among the common 

 species of Senecio, Sedum, Pedicularis, &c., but two additions to the 

 flora of Colorado were noticed : Arenaria saxosa of New Mexico and 

 Corydalis Casea na of the Sierra Nevada. To find these plants growing with 

 species of so northern a habitat as Calypso borealis, Lister a cor data, and 

 Aspidium Filix-mas was very interesting. The Corydalis prefers the banks 

 of the little mountain-streams and cold springs in the shade of the for- 

 ests of Abies Engdmanni and grandis. Here it reaches a height of 5 

 feet ; the finely-dissected leaves are 2 feet and more long, forming a 

 very handsome foliage-plant, but its blue-tinged flowers lack clearness 

 of color. 



In the valleys of the Los Pinos, Florida, and Animas, at about 7,000 

 feet altitude, the first Decided change appears in the flora. Plants not 

 before known to exist in Colorado become common, and in some places 

 form the greater part of the vegetation. Bushes of Fendlera rupicola 

 10 feet high grow upon the bluff-sides ; thickets of Peraphyllum ramosis- 

 simum are very plenty, now full of its long-stemmed fruit called by the 

 few white settlers wild crab-apple. Conspicuous among the plants 

 which mark the change in the flora are Ehamnus Californicus, Hosackia, 

 Yucca baccata. 



Southwestern Colorado, an extent of country of very different altitudes, 

 and embracing within its limits various conditions of soil, moisture, &c., 

 of course has a varied flora. The flora of the alpine and subalpine 

 regions of the Sierra La Plata, the only high mountains in oar district, 

 like that of the Piedra and Los Piuos Mountains, is similar to that of 

 equal altitudes in Northern Colorado. 



To the alpine flora, the only addition is a bright-pink clover, named 

 by Mr. Watson Irifolium Brandegei. The subalpiue flora compared 

 with that of the eastern slope has a greater abundance of Rubus 

 Nutkanus, Pyrus sambucifolia, Prosartes trachycarpa. 



The Mesa Yerde, a plain of two hundred square miles, raised 

 nearly 1,000 feet above the surrounding country, is a prominent 

 topographical feature of Southwestern Colorado. Its surface is per- 

 fectly dry ; the showers from the La Plata Mountains rarely wet- 

 ting it except upon the northern edge. Jumperus occidentalis covers 

 almost the whole mesa, and it is to the abundance of this un- 



