Dr. Engelmann on the Cereus giganteus of California. 3 
Lowest and upper radial spines 6 to 12 lines long, sometimes 
the upper ones with a few additional, shorter, flexuous, setaceous 
spines: lateral ones 12-18 lines long, the lower ones longest; the 
four lower central spines straight or very slightly curved down¬ 
wards, 20-30 lines long; the two upper central spines 15 to 18 
lines long. The stoutest spines are one line in diameter, their 
bulbous base being fully twice as thick. The old spines together 
with the whole areola readily come off in one bunch, but general 
ally the 6 central spines fall off first, leaving the radiating ones 
appressed to the stem, till finally they also fall away. 
The flowers are produced near the summit of the plant, but 
not'on it, and the fruit is usually 6-12 inches from it. 
The dried flower communicated by Mr. Thurber is 3 inches 
long; but the drawing represents the flowers as fully 4 inches in 
length and diameter. The ovary in the dried specimen is Jths of 
an inch long; the lower naked part of the tube 1 inch, the upper, 
staminiferous much widened part jths of an inch long. Upper 
sepals fleshy, greenish white, Jths of an inch long, below 2, 
above 4 lines wide. Petals of a light cream color, an inch long, 
6-7 lines wide above, very thick and fleshy, and very much 
curled. Filaments light yellow, adnate to the upper half of the 
tube: anthers 08 to 0*9 of a line long, linear, emarginate at the, 
base and apex. Style not seen ; the drawing represents the nu¬ 
merous (15-20?) stigmata as half an inch long, suberect, of a 
green color. The flowers appear to be open night and day, and 
probably for several days in succession. 
The fruit sent by Mr. Thurber (in alcohol) is obovate2J inches 
long, by 1J in diameter, beset with about thirty scales, having 
short brownish wool in their axils, but entirely destitute of spines. 
Mr. Thurber informs me that this specimen is unusually long : 
the fruit, he says, is usually 2 or 3 inches loqg by 1J to 2 in 
diameter; the color is green, reddish towards the summit; the 
remains of the flower fall off, leaving a broad and convex scar. 
The pericarp has the hardness of a green cucumber, somewhat soft¬ 
er towards the apex, and is about 2 lines thick : it bursts open on 
the plant with 3 or mostly 4 irregular, interiorly red valves, which 
spread horizontally, and appear like a red flower when seen at a 
distance, which accounts for the report of this species having red 
flowers. The crimson-colored and rather insipid pulp has the con¬ 
sistency of a fresh fig ; it completely separates from the rind, and 
drying up from the heat of the sun, falls to the ground, or is beat¬ 
en down, when it is collected by the natives and rolled into balls, 
which keep several months, or is pressed for the thick molasses- 
like sacharine juice which it contains. The innumerable seeds 
are 0-7 to 0 8 lines long. 
Another, apparently nearly allied species, was collected in 
Northern Sonora. From the half of a flower before me, together 
2 3 
