VOL. .] Cactacee of Baja California. 21 
globular, dull red when ripe, acid and pleasant to the taste. Seeds 
very rough, embryo slightly hooked. The fruit much resembles in 
form and color that of C. gummosus, the well known pitahaya of 
Lower California. It is more acid in flavor and on that account 
not so much esteemed. Within the color is bright purple, similar 
to that of a ripe watermelon. As far as known, its habitat appears 
to extend from San Gregorio to below Santa Margarita Island 
along the coast in sandy situations. It perhaps does not belong 
to the Cape Region flora. 
A species of Echinocereus, bearing dull red flowers, is abundant 
at Todos Santos and La Paz. It does not grow on the peninsula 
north of these places. 
A species of Cereus with long stems hanging from the rocks 
grows in the Sierra dela Laguna. The spines are few and short, 
the stems are prominently angled and their color light green. 
Neither flowers nor fruit were seen. 
OPUNTIA (PLATOPUNTIA) sp. The common species of the 
southern part of the peninsula. 
OPUNTIA PROLIFERA Engelm. San José del Cabo. 
OPUNTIA ROTUNDIFOLIA. Erect, slender and weak, ramose, 
2-3 m. high, supported by bushes; stems cylincrical, woody, 1-1% 
cm. thick; joints 6-10 cm. long; spines none; sete numerous, 
retrorsely barbed, 3-5 mm. long, usually reddish brown; pulvilli 
gray, woolly, remote; leaves sessile, fleshy, round-ovate, acute, 
2-3 cm. long and broad; flowers about 4 cm. in diameter; sepals 
few, spatulate, short; petals few, yellow, broad and entire; style a 
little shorter than the petals, with (in the single flower) four branches; 
fruit slenderly clavate, about 5 cm. long, 4-6 mm. wide, with 15-20 
areola, setae-bearing like the joints; seeds few, flattened, whitish, 
densely covered with white hairs about as long as the diameter of 
the seed, apparently somewhat deciduous in age, commisure readily 
separating, embryo curved about small albumen, the thick coty- 
ledons somewhat obliquely incumbent.—Not uncommon in the 
Cape Region at low elevations. At Todos Santos and La Paz in 
January it was in fruit and all the leaves had fallen excepting a few 
; : at the ends of young growing shoots, but in September at San José 
_ del Cabo the whole plant was covered wlth a mass of thick green 
leaves, amongst which a few yellow flowers were visible. In January 
the setae were numerous and so easily detached that many fell 
while cutting specimens, and the inhabitants say the wind will blow 
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