CACTACEZ OF WHIPPLE’S EXPEDITION. 161 
the unfavorable season of the year (October — March) during our journey through regions of these cacti, we were 
unable to procure the flower or fruit of any of these plants. In our friendly correspondence with Dr. Engelmann, 
I insist that C. Nadia and ©. conoideus are distinct species; and (from analogy only) I assume that when the 
flower of C. conoideus is obtained, it will be found to be a purple, while that of C. phaniceus is crimson. Time and 
observation, however, are the only decisive arbiters of such controversies, 
Subgen. EUucEREUSs. 
Of Cereus proper only one species was seen, namely: : 
11. Cereus aicantEeus, Engelm.: Williams’s River to the Colorado of the west, Feb. 4 to Feb. 22, 1854. 
This is the most northern true Oireus that we have, being found as high as latitude 34°, while C. Greggit and C. E: 
are found only a little above latitude 32°. This plant has a considerable range, extending south from this place to 
near latitude 28°, in the vicinity of Guaymas Sonora. The fruit under the Mexican name of pitajaya — pronounced 
pit-a-zi-ah or pit-ai-yah — is a great source of sustenance to the Mexicans and Indians of the regions where it grows. 
Conserves and molasses, or syrup, are made from them, which are preserved during the winter season for future use. 
They are very pleasant to the taste in a fresh state. As the fruit grows near the top of the tree, at an altitude of 25 to 
50 feet, and being very large and pulpy, if permitted to ripen and drop to fe ground they burst and are almost ren- 
dered unfit for use. The Indian mode of collecting them is to take a long light pole, make a fork at the top by tying 
a short piece to it, by which they contrive to bring them within reach. Birds and every kind of animal and 
meet that can reach them are so fond of them that many of them are thus destroyed. My friend, Mr Schott, [37] 
of the Mexican Boundary, who has lately returned from that desolate but rather interesting region, informs me 
that still farther south thts interesting plant is replaced by another not so large, but still a great cactus. This is 
very probably the one collected by Mr. Thurber, described and named by Dr. Engelmann, in Silliman’s Journal, 
. Thurberi. The pitajaya of this species, according to Mr. Schott, is the principal support of the Papigo Indians. 
It is much larger, sweeter, more juicy than that ot the C. giganteus. The color of the pulp is also of a much 
righter 
In consequense of the remote and inhospitable region of this curious and interesting cactus, our acquaintance 
with it became very gradual. Dr. Engelmann thinks that-Baron von Humboldt, in his work on New Spain, must 
h ad reference to this plant ; but this is quite uncertain, because no characteristics are given of his cacti (organos 
del Lunal) except size and edible fruit, and many other large species of both Cerei and Opuntie are long and well 
known to yield them. In 1846 Major Emory first collected seeds and made figures of it, which, on being presented to 
Dr. Engelmann, he was unable to pronounce it a true Cereus, and at that time very appropriately named it. Subse- 
quently (winter and spring of 1852 Dr. Parry, under Major Emory, visited that region, collecting spines, wood, etc., 
and making copious notes on the ground, enabled Dr. Engelmann to give a good diagnosis of it. Still Dr. Parry was 
unable to procure the flower or fruit on account of the lateness of the season, It was reserved for Mr. Thurber, who 
repassed this region in the summer of 1852, to collect complete specimens; and Dr. Engelmann, in a subsequent 
number of Silliman’s Journal, has given a complete description of it. (Vide Amer. Journ. Vol. XVII. 2d Series, 
March, 1854.) 
To the several excellent accounts given of this tree by Dr. Engelmann, little of interest can be added. As 
noticed by Dr. Parry and Dr. Engelmann, the number of ribs at the base is about 12, and they “increase upward, by 
bifurcation and addition,” to the lernett circumference of the tree, which is about 15-18 feet from the ground, and 
where also usually the few branches are given off. Here the ribs sometimes number 30, and from this point upward 
they decrease in number to 18-20. The wood mA the base of old specimens becomes a perfect hollow cylinder ; and 
from thence upward to the first branches, instead of being solid, it regu a reticulated. network of gta of w 
continuing the hollow cylinder, as is seen on a smaller scale in the wood of Opuntia arborescens. ese trees in 
abundance give the.landscape a very peculiar appearance, and from their oe and entire pieces to any others, 
at first is not only curious but pleasing ; but as the eye becomes accustomed to it, a gradual transition takes place in 
one’s feelings, and from being pleasing, they at last become monotonous and repulsive. This feeling, however, may be 
somewhat accounted for by the sterility of the surrounding land. As far as the eye can reach, in the valleys or on the 
mountains, little else but rocky boulders, and the stately yet awfully sombre aspect of the Cereus giganteus, can be seen. 
OPUNTIA, Tovry. 
Subgenus 1. Pxratopuntis, Engelm. 
OPUNTIA ENGETMANSI, Salm. At Delaware, about 170 miles west of Fort Smith, a specimen of this plant 
was observed about 4 feet high. This seems to be the northern limit of a species which is aids spread from lower 
Mexico to the mouth of the Rio Grande, and on both sides of that river, northward and southward. In the southern 
regions it grows much taller than in the north. 
21 
