CACTACEZ OF WHIPPLE’S EXPEDITION. 173 
breviter albo-tomentosis, setarum straminearum penicilla paro brevi, aculeis ex imo —— esac elongatis corneis 
s. fuscis laxe stramineo s, aurantiaco-vaginatis, adjectis subinde supra aculeis minoribus 1- acca ovata tuberculata 
pulposa flava pulvillos 15-20 majusculos albo-tomentosos setosos gerentibus, umbilico wags immerso, seminibus 
subregularibus marginatis. (Plate XX. fig. 1. 
‘About Albuquerque, where Dr. Wislizenus had already collected it in 1846 ; apparently extending into [53] 
Mexico, as Dr. Gregg collected what seems to be the same species about San Luis Potosi. Shrub 3-5 feet high ; 
lower part of stem 1-14 inch thick, covered with scaly, light-yellowish-brown bark ; older branches smooth terete, 
younger ones 3-4 lines in diameter, strongly tuberculated ; tubercles 6-9 lines long. Leaves slender, about 3 lines long, 
and apparently somewhat persistent, as they are sometimes found adhering, though withered, even to fruit-bearing 
branches, which, of course, are over a year old; the same, though to a less extent, is sometimes seen in 0. frutescens. 
Pulvilli unusually large ; bristles in the young ones forming a small but distinct bunch at the upper edge of the areola, 
but disappearing on the older joints, — contrary to the usual occurrence, when the bristles become stouter and more 
numerous in older joints. Spines 1-24 inches long, dark, with very loose and glistening sheaths; second or smaller 
spine sometimes lateral, but usually above the principal one, not below it, as in most others. Flower unknown. 
Fruit ovate, 8 or 9 lines long; the pulvilli often bear 2-5 obtuse bodies, almost hidden in the tomentum, apparently 
glandular, but of a Sineutes: structure. Seeds 12-15 in each fruit, about 2 lines or a little more in diameter; 
— broad, prominent, forming a distinct, somewhat spongy rim. (See Plate XX. fig. 1, and Plate XXIV. 
figs. 5.) 
ie Dr. Wislizenus’s Report the long-spined form of 0. frutescens was confounded with this species. It is possible, 
however, that 0. vaginata, as described here, may be a stouter, tuberculated form of 0. frutescens, with lighter-colored, 
tuberculated fruit and larger seed. 
27. O. FRuTEScENS, Engelm. This well-known species was observed from Laguna Colorado, 60 miles east of 
the Pecos, to Williams’s River, a branch of the great Colorado, always with the same characters. The bark is scaly, 
almost papery, with a silvery reflection; the wood shows the medullary rays very distinctly, especially 5 of them ; 
much less the annual layers. Fruit deep scarlet, smooth, small, sometimes almost obliterated pulvilli, 5-9 lines long. 
Seeds 5-10, about 1} lines in diameter, with a narrow and often acute margin. The forms collected on the expedition 
belong to var. a. longispina; the var. 8. brevispina has been observed only in Texas and northeastern Mexico. 
(See Plate XX. figs. 2-5, and Plate XXIV. figs. 16-19.) 
EXPLANATIONS OF THE PLATES OF CACTACEA. 
Plate I. Ecnrnocactus Wurrrtel, E. & = ¢ fie 3, be plant ; ase 2, bunch of spines of the usual size; [54] 
fig. 83, same, uncommonly large and broad ; fig. 4, same, lateral view ; fig. 5, e, very young; fig. 6, aa natural 
size, b magnified 8 diameters, ¢ part of the ‘surfioe still more magnified to exhibit the tuberculated ap 
e II. figs. 1-2. Ecurnocactus poLtyancistrus, E. & B.: 1, upper part of a rib, with older and Lene bunches of 
— bee youngest one with a flower-bud in the axil ; 2, one of the largest and most fully developed bunch 
Figs. 3-5. Ecnrnocactus LEConTEI, E.: 3, part of a rib, with 2 bunches of spines; 4, a single Sela of spines from 
another specimen ; 5, seed, — a natural size, 6 magnified 8 diameters, ¢ part of the surface still more magnified to exhibit the 
oval pits 
Plate ITI. figs. 1-2. Ecntwocacrvs Wis izent, E.: 1, side view ofa bunch of spines; 2, seed, — a natural size, 6 magnified 
8 Pinca c seb of the surface still more magnified to exhibit the reticulation. This species, collected by Captain Whipple 
on the Gila, and common about El Paso, on the Rio Grande, has been introduced here to show those characteristics which dis- 
tinguish it from the nearly allied EZ. LeContei on the foregoing plate. 
Fig. 8. Ecurnocacrus Emorrl, E.: two bunches of spines on part of a ri 
Figs. 4-6. Ecutnocactus potycepHatus, E. & B.: 4, part of a rib, eee 3 bunches of short, _ and straightish 
spines; 5, a young bunch of spines of unusual dimensions and much curved, with a woolly fruit in the axil; 6, seed, —a natu- 
ral size, b magnified 8 diameters, c part of the surface more magnified to show the warty appearance, d seed after the removal of 
the outer integument, embryo, together with a considerable quantity of albumen in the endopleura, e embryo curved with 
accumbent cotyledons. 
Plate IV. figs. 1-3. Crrrvs pH@nicevs, E.: 1, upper part of a head bearing a flower; 2, a bunch of spines of the 
usual size ; 3, part of a rib, with 3 bunches of spines from an uncommonly large form 
Figs. 4-5. CEREUS PH@NICEUs, subsp. conorpEvs, E. & B.: 4, u pyar: pert ole tend: 5, part of a rib, with 2 bunches 
of spines. 
