54
CACTACEJE.
being surrounded on the lower side by tbe radial spines of the cluster above which it is developed; theyare four to four and a half inches long, and two and a half inches broad when expanded. The ovaryis ovoid, an inch in length, and rather shorter than the stout tube of the flower; it is covered like thebase of the tube by thick imbricated green scales with small free triangular acute scarious mucronatetips furnished in their axils with short tufts of rufous hairs and occasionally with clusters of shortchartaceous spines. The scale-tips lengthen above the base of the tube and gradually pass into thinoblong-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 theflower. 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, theexterior rows being joined below into a long tube which lines its bottom, from which rises the stoutcolumnar style surrounded at the base by a circle of oblong nectariferous glands and divided at the apexinto twelve or fifteen green stigmas. The fruit ripens in August and is ovate or slightly obovate, twoand a half inches long, one inch and a third broad, and covered with the remote persistent tips of thescales of the ovary; the top is truncate and covered by the depressed pale scar left by the falling ofthe flower. When ripe it is light red and separates irregularly into three or four fleshy valves whichare one sixth of an inch thick and bright red on their inner surface, and in opening disclose the brightscarlet juicy mass of the enlarged funiculi through which are scattered innumerable seeds; these areobovate, rounded, one sixteenth of an inch long, and covered with a thick lustrous dark chestnut-browncoat. After the bursting of the fruit the juicy central mass dries and falls to the ground, the valves ofthe pericarp, which remains for some time longer on the stem, turning back and presenting the appear-ance of a star-shaped red flower. 1
Cereas giganteus is distributed from the valley of Bill Williams River through central andsouthern 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, towhich its tall sombre sentinel-like shafts, which look as if they had been cut from stone, give a peculiarand most interesting appearance. 2
The wood of the columns is strong, very light, soft and rather coarse-grained, with a satiny surfacesusceptible of receiving a fine polish; it contains numerous conspicuous medullary rays and broad bandsof open cells marking the inner portion of the layers of annual growth. It is light brown tinged withyellow, 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, 3 who collect themwith long forked sticks, and who dry and eat them or press them when fresh to obtain their thickmolasses-like juice, which they preserve for winter use.
Cereus giganteus was discovered on the 1st of November, 1846, in a gorge of the Gila Rivernear the mouth of the San Francisco in Arizona by Lieutenant-Colonel William H. Emory 4 of the
1 The accompanying plate was engraved from drawings madeby Mr. Faxon of the flowers and fruit of Cereus giganteus producedon the top of a tree sent to me in Brookline from Phoenix , Arizona ,by Mr. Thomas H. Douglas. The top of the stem, which had beencut off two or three feet from the apex, was placed as soon as itarrived on a hoard in a warm dry greenhouse where the smallflower-buds with which it was covered grew and opened, and after-ward produced fully developed fruit with perfect seeds.
2 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 MilitaryReconnaisance from Fort Leavenworth in Missouri to San Diego i nCalifornia ), opposite pp. 72, 74, 76, 78 ; in the frontispiece to partii. vol. ii. Report on the U. S. Mexican Boundary Survey (Ex. Doc.No. 108, 34th Congress , 1st Session) ; in the Treasury of Botany , x -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, Mem. Am. Acad. n. ser. v. 305.
4 See iv. 60.