D4 SILVA OF NORTH AMERICA. CACTACE. 
being surrounded on the lower side by the radial spines of the cluster above which it is developed; they 
are four to four and a half inches long, and two and a half inches broad when expanded. The ovary 
is ovoid, an inch in length, and rather shorter than the stout tube of the flower; it is covered like the 
base of the tube by thick imbricated green scales with small free triangular acute scarious mucronate 
tips furnished in their axils with short tufts of rufous hairs and occasionally with clusters of short 
chartaceous spines. The scale-tips lengthen above the base of the tube and gradually pass into thin 
oblong-ovate or obovate sepals, mucronate or rounded at the apex and closely imbricated in many ranks. 
The petals, which vary in number from twenty-five to thirty-five, are obovate-spatulate, obtuse, entire, 
thick and fleshy, creamy white, two thirds of an inch long, and much reflexed after the expansion of the 
flower. The stamens are exceedingly numerous, with long slender filaments and linear anthers emar- 
ginate at both ends; the filaments are united for half their length to the walls of the calyx-tube, the 
exterior rows being jomed below into a long tube which lines its bottom, from which rises the stout 
columnar style surrounded at the base by a circle of oblong nectariferous glands and divided at the apex 
into twelve or fifteen green stigmas. The fruit ripens in August and is ovate or slightly obovate, two 
and a half inches long, one inch and a third broad, and covered with the remote persistent tips of the 
scales of the ovary ; the top is truncate and covered by the depressed pale scar left by the falling of 
the flower. When ripe it is ight red and separates irregularly into three or four fleshy valves which 
are one sixth of an inch thick and bright red on their inner surface, and in opening disclose the bright 
scarlet juicy mass of the enlarged funiculi through which are scattered innumerable seeds; these are 
obovate, rounded, one sixteenth of an inch long, and covered with a thick lustrous dark chestnut-brown 
After the bursting of the fruit the juicy central mass dries and falls to the ground, the valves of 
the pericarp, which remains for some time longer on the stem, turning back and presenting the appear- 
coat. 
ance of a star-shaped red flower.' 
Cereus giganteus is distributed from the valley of Bill Williams River through central and 
southern Arizona to the valley of the San Pedro River, and southward in Sonora, scattered in consid- 
erable numbers through the crevices of low rocky hills and over the dry gravelly mesas of the desert, to 
which its tall sombre sentinel-like shafts, which look as if they had been cut from stone, give a peculiar 
and most interesting appearance.” 
The wood of the columns is strong, very light, soft and rather coarse-grained, with a satiny surface 
susceptible of receiving a fine polish ; it contains numerous conspicuous medullary rays and broad bands 
It is light brown tinged with 
yellow, and when perfectly dry has a specific gravity of 0.3188, a cubic foot weighing 19.87 pounds. 
The columns, which are almost indestructible in contact with the ground and little affected by the at- 
mosphere, are largely used for the rafters of adobe houses, for fencing, and by the Indians for lances, 
bows, etc. ‘The pulp and seeds are devoured by birds. and are prized by the Indians,? who collect them 
with long forked sticks, and who dry and eat them or press them when fresh to obtain their thick 
molasses-like juice, which they preserve for winter use. 
Cereus giganteus was discovered on the Ist of November, 1846, in a gorge of the Gila River 
near the mouth of the San Francisco in Arizona by Lieutenant-Colonel William H. Emory‘ of the 
of open cells marking the inner portion of the layers of annual growth. 
1 The accompanying plate was engraved from drawings made 
by Mr. Faxon of the flowers and fruit of Cereus giganteus produced 
on the top of a tree sent to me in Brookline from Phenix, Arizona, 
by Mr. Thomas H. Douglas. The top of the stem, which had been 
cut off two or three feet from the apex, was placed as soon as it 
arrived on a board in a warm dry greenhouse where the small 
flower-buds with which it was covered grew and opened, and after- 
ward produced fully developed fruit with perfect seeds. 
? Portraits of Cereus giganteus displaying the habit of the plant 
and the appearance of the country which it inhabits can be found 
in Ex. Doc. No. 41, 30th Congress, 1st Session (Notes of a Military 
Reconnaisance from Fort Leavenworth in Missouri to San Diego in 
California), opposite pp. 72, 74, 76, 78 ; in the frontispiece to part 
ii. vol. ii. Report on the U. S. Mexican Boundary Survey (Ex. Doc. 
No. 108, 34th Congress, 1st Session) ; in the Treasury of Botany, i. 
256; in the Flore des Serres, x. opposite p. 24 ; xv. opposite p. 187; 
and in the frontispiece to vol. vi. of the Rep. of the U. S. Geographi- 
cal Surveys West of the One Hundredth Meridian. 
8 Thurber, J/em. Am. Acad. n. ser. v. 305. 
+ See iv. 60. 
