Opuntia. CACTACE^E. 247 



angular, variously colored : large purple flowers open only in sunlight : ovary and 

 fruit with 25 to 30 spiny areolce, 15 to 20 upper sepals, and as many lance-oblong 

 petals: stigmas about 12, erect. Am. Jour. Sci. 2 ser. xiv. 338; Cact. of Pacif. 

 E. Eep. iv. 35, t. 5, fig. 4-10. 



From the eastern slopes of the Southern Sierra Nevada, at San Felipe, into Arizona and Utah, 

 apparently abundant, Parry, Newberry, Palmer, and others. Heads usually 4 to 6 together, 5 to 

 10 inches high, 2 or 3 thick ; outer spines to f , inner 1 or 2 inches long ; flowers 2^ to 3 inches 

 long and wide, appearing in June. 



2. Prismatic or cylindric, mostly branching : flowers usually longer than wide : 

 stigmas whitish : seeds obovate, usually smooth or pitted : embryo with foli- 

 aceous curved cotyledons. EUCEREUS. 



* Ovary and fruit spiny. 



2. C. Emoryi, Engelm. Stems erect, branching from the base, cylindric, with 

 16 to 20 ribs, closely set with prominent hemispherical areohe bearing numerous 

 (30 to 50) thin straight yellow spines ^ to 1 or If inches long; the 3 to 6 inner 

 ones longer and deflexed : flowers short, greenish yellow, crowded on one side of the 

 top of the stems : ovary with few short spines, which become formidable upon the 

 subglobose fruit. Am. Jour. Sci. 1. c. ; Cact. Mex. Bound. 40, t. 60, fig. 1-4. 



On the gravelly mesas near the sea-shore at San Diego (Parry, Agassiz, Hitchcock), and quite 

 abundant on rocky hills from Los Angeles to the Salinas Valley (Brewer), and into the Peninsula 

 to Kosario, Gabb. Stems 2 to 4 feet high, H to 2 inches thick, often from a prostrate rooting 

 base, and forming dense thickets ; areolaj 2 lines wide and 3 or 4 lines apart, densely covered 

 with the thin sharp and very brittle spines ; flowers usually on one side only, like those of Pilo- 

 cereus, 1 J to 1^ inches long and a little less wide ; fruit about an inch long ; seeds over a line 

 long, shining, minutely tuberculate. 



* * Ovary and fruit scaly. 



C. GIGANTEUS, Engelm., 15 to 30 or even 40 feet high, very stout, with few erect branches 

 towards the upper part, cream -white short-tubed flowers, and large oval edible fruit, which at 

 maturity bursts irregularly, and 



C. THURBERI, Engelm., 10 to 15 feet high, more slender, with many equally high ascending 

 branches from the base, similar flowers, and larger globose delicious fruits, are lound in the 

 adjoining territories of Arizona and Lower California, and may be looked for in this State. 



3. Tall, cylindric, mostly unbranched ; upper flower-bearing portion loith more 

 crowded areolce and longer denser thinner bristly or hairy spines : flowers 

 short : seeds as in the last. PILOCEREUS. 



C. SCHOTTII, Engelm., 4 to 10 feet high, the lower part 5-angled, with distant areolae and few 

 very short and stout spines ; the upper flowering portion deeply 5-ribbed, with close-set areolse 

 bearing numerous setaceous spines, almost hiding the small flowers and small berries, from 

 the same localities as the last two species, may also be found in Southern California. 



4. OPUNTIA, Tourn., Miller. 



Tube of the flower very short, cup-shaped. Petals spreading or rarely erect. 

 Ovary with bristle-bearing areolse in the axils of small terete deciduous sepals. 

 Berry succulent or sometimes dry, marked with bristly or spiny areolae, truncate 

 with a wide umbilicus. Seeds large, white, compressed, with the embryo coiled 

 around the albumen : cotyledons large, foliaceous. Articulated much-branched 

 plants, of various shapes, low and prostrate, or erect and shrub-like ; young branches 

 with small terete subulate early deciduous leaves, and in their axils an areola with 

 numerous short easily detached bristles and, usually, stouter spines, all barbed. 

 Flowers on the joints of the previous year, on the same areolce with the spines, 

 mostly large, open only in sunlight. Fruit often edible, often large. 



