4 BOTANY. 
Nevada mountains of California. The real grass-leaved dasylirion was first seen here, on the 
bluffs of the Llano Estacado. It is identical with the one found on the San Pedro, or Devil’s 
river, in Texas. There is another species, with the leaves and habit somewhat of a Yucca, 
named D. graminifolia, I suppose because it does not resemble a grass. A rosaceous shrub (Cerco 
carpus) and a shrubby oak (Q. Zmoryi?) are also common under the bluffs. We have not now 
the means at hand to determine whether they are the same as occur in lower Texas and New 
Mexico. Eriogonez, another characteristic tribe of plants peculiar to dry climates, begin here 
to make their appearance in considerable numbers. Mentzelias and asteroid composites are also 
quite abundant. An Ephedra, much used as a diuretic, especially for horses, was first seen 
here. The genus is also common in lower Texas, whens I know two or Dusen distinct species 
of it. 
Section IV. Tucumcari and Pecos ener eee the Waters of these two valleys flow into 
the Gulf of Mexico, by widely-separated channels, yet they may well be considered in one dis- 
trict—being included in the space of about one hundred and seventy miles, from Fossil creek to 
the dividing highlands between the Rio Pecos and Rio Grande del Norte. 
At Tucumcari we have a broad, beautiful, and fertile valley, abounding in most luxuriant 
grasses, and extending north to the Canadian,‘ but its exact limits we had not time to explore. 
Although the timber is somewhat scarce, yet, ascending the hills on either side, cedars and 
pifion become much more abundant, and both attain a higher stature than on the Llano Esta- 
cado. Along the banks of the streams there are a few cotton-woods and box-elders of very 
pretty size. The Gallinos, whose outlet is south into the Pecos by narrow defiles near our line, 
is a beautiful, bold, clear, running stream, affording water at all seasons of the year, while the 
Tucumcari and Pajarito creeks, in the immediate vicinity of the Tucumcari hills, flowing north 
into the Canadian, will.afford water doubtless nearly all the year. At any rate, when we 
passed, (21st September,) there was plenty, flowing in a rapid, turbid stream. The water of 
Laguna Colorado, which is near, or forms, the sources of these streams, is somewhat brackish. 
We collected here, for the first time, specimens of another shrubby cactus, (Opuntia frutes- 
cens,) which is so abundant all over southern New Mexico and Texas, as far south as Eagle Pass 
and San Antonio. It is a very ornamental species, especially when loaded with its scarlet 
berries. On the hills in this region were found, and collected, several new mamillaria ; 
beautiful flowering and fruiting specimens of which are now growing in the Congressional 
gardens, in Washington. Opuntia Engelmanni, which is probably the most widely spread of 
the whole tribe of American cactacex, was first detected in the rocky cafions of the Gallinos. 
Fallugui paradoxa and Fendlera rupicola, two beautiful shrubs, are common here; both of them 
common to Texas also, There are, likewise, several other Texan plants in this region, among 
them a Parthenum, Thymophylla greggi, and a great variety of leguminous and asteroid plants. 
Several species of eriogonie also make their first appearance here. As their geographical limits 
extend westwardly some distance, most of the eriogoniz which were collected here will most 
probably prove to be those which are figured, and well characterized, by my excellent friend 
Dr. Torrey, in Captain Sitgreaves’ report of the Zuiii expedition. As we proceed a little further 
west, we come to the Pecos valley, where, in addition to the pijion and cedars met with before, 
and already mentioned, we find pine trees of a majestic size, (Pinus brachyptera, Yngl.,) that 
_ are as valuable for inher as almost any in the world. 
The Pecos river is here clear and rapid, its waters pure and sweet, forming quite a contrast 
to those at the several crossings from San Antonio to El Paso, where they are always turbid, 
brackish, and disagreeable. Indeed, by some travellers on its lower borders, and on some 
maps, this river, from these circumstances, has acquired the name of Puerco, the Spanish 
appellation for muddy waters. There, its valley, for hundreds of miles, is a blank and dreary 
waste, with scarcely a shrub to relieve the eye of the traveller ; here, its fertile banks are dotted 
with innumerable small plantations, and towns, so characteristic of New Mexico. 
_ ‘This river, with the Gallinos, will form a nover-failing supply of water for the erection of all 
