228. CEEEUS GIGANTEUS SAGUARO. SUWAERO. 23 



usually furnished with remarkable spines springing in fascicles from ariolae in 

 the axils of leaves or absent leaves. Flowers perfect, usually solitary, often large 

 and showy, ephemeral; sepals numerous, the inner petal-like, united below for 

 considerable length into a tube adnate to the ovary; petals delicate, in two or 

 more rows united below with the sepals; stamens numerous in several rows, with 

 long filiform filaments and introrse two-celled longitudinally dehiscent anthers; 

 ovary inferior, one-celled with parietal placentae and numerous anatropous 

 ovules; style simple, elongated and stigmas as many as the placentae. Fruit a 

 pulpy umbilicate berry, smooth or furnished with spines and containing numer- 

 ous seeds, with or without albumen, buried in the pulp. 



A large order of few genera, but many species, of plants of very peculiar 

 aspect, confined quite exclusively to the American continent, natives of dry arid 

 regions and most abundant in or near the tropics. 



GENUS CEREUS, HA WORTH. 



Leaves absent. Flowers perfect, as long as wide or longer, large and showy, 

 sometimes nocturnal and very fragrant; calyx usually elongate with numerous 

 spirally imbricated lobes and a nectiferous tube; petals numerous, cohering with 

 the top of the calyx tube, spreading, recurved, white or red, imbricated in aesti- 

 vation; stamens very numerous and inserted in the calyx tube with filiform fila- 

 ments and minute oblong introrse 2-celled anthers; ovary inferior, 1 -celled, with 

 elongate filiform style divided into numerous radiating stigmatic branches and 

 containing many horizontal ovules arranged on parietal placentae. Fruit 

 baccate, covered with scales or spines, often edible, many seeded. 



Genus consists of trees or shrubs of about 200 species, with watery juice, and 

 ribbed, columnar erect stem, or low, spreading or climbing and 3-7-angled or 

 cylindrical or globose stem, spine-bearing from areolae on vertical ribs. The 

 name Cereus is the Latin for candle in allusion to the erect candle-shaped form of 

 some of the individuals. 



228. CEREUS GIGANTEUS, ENGELM. 



SAGUARO. SUWARRO. GIANT CACTUS. 

 Gei.,iesencactus; Fr., Cactus gigantesque; Sp., Saguaro. 



SPECIFIC CHARACTERS: Flowers (May to July) in ample clusters at or near 

 the top of the plant, not from any preformed areolae but bursting through the 

 epidermis just above the bunches of spines, 4-4 in. long and about half as broad 

 when fully expanded ; calyx tube stout and covered with thick imbricated green 

 scales, those lowest down (over the ovary) with free acute mucronate tips and 

 clusters of short hairs on spines in their axils. Farther up the scale tips lengthen, 

 become thinner, obovate in outline and closely imbricated ; petals numerous, 

 creamy white, thick, about f in. long, rounded or obtuse and entire at apex, 

 much reflexed after expansion ; stamens very numerous, with long slender fila- 

 ments ; style stout, columnar, with nectiferous glands at its base and dividing at 

 its summit into 12 or 15 green stigmas. Fruit ripe in August, is oblong, light 

 red, truncated and depressed at apex, about 2| in. long, covered with persistent 

 scales and finally bursting into three or four valves, revealing a juicy mass of 

 innumerable dark brown seeds about in. long. After the seed-bearing contents 

 drys and falls away, the dry star-shaped pericarp remains for a time longer on 

 the plant. 



These strange columnar trees, seeming at first glance more like dead 

 stubs than trees, are sometimes 50 or 60 ft. (18 m.) in height, and 

 2 ft. (0.60 m.) in diameter, somewhat below the middle, and tapering 

 gradually both ways. They are branchless or furnished with one or 

 very few large branches which grow out and then upwards generally 

 parallel with the main stem. It is prominently ribbed lengthwise 



