OPUNTIA. 



Plate x, figures 2 and 3, are from paintings showing different flower-colors, made at 

 the Desert Laboratory, Tucson, Arizona; figure 4 represents a fruiting joint of a plant 

 collected by F. Gilman at Sacaton, Arizona; and figure 5 represents a leaf -bearing joint 

 of the same plant; plate xn, figure 2, is from a photograph of the plant in the Tucson 

 Mountains, Arizona, by Dr. MacDougal. 



32. Opuntia prolifera Engelmann, Amer. Journ. Sci. II. 14: 338. 1852. 



Stems i to 2 meters high, the trunk and old branches terete and woody; terminal joints 3 to 

 12 cm. long, easily breaking off, fleshy, covered with short, more or less turgid tubercles; spines 6 

 to 12, brown, 10 to 12 mm. long; glochids pale; flowers small; sepals orbicular, obtuse, dark red; 

 petals red; filaments yellow; style stout; stigma-lobes red; ovary i cm. long, strongly tuberculate; 

 upper areoles bearing 2 to 6 reddish spines or the joints naked throughout; fruit proliferous, 3 to 

 3.5 cm. long and often without seeds; seeds, if present, large, regular, 6 mm. broad. 



Type locality: Arid hills about San Diego, California. 



Distribution: Southern California and coast of Lower California. 



The range of this species is not well known. We have referred here, with some doubt, 

 specimens collected by Dr. Rose on Guadalupe Island, off the coast of Lower California, as 

 well as specimens from the south end of Lower California, but we have seen no flowers from 

 these Lower California collections. A peculiar form less than 5 dm. high with bluish-green 

 joints and small seeds, from near Newport, Orange County, California, deserves further study. 



This species, although common in southern California, has never been fully and accu- 

 rately described. It is often confused in collections with 0. scrpcutina, with which it grows, 

 although they are very different. 



In greenhouse specimens the joints and spines are not well developed. 



Illustration: Meehan's Monthly 3 : pi. i. 



Plate xi, figure 2, represents a flowering joint of a plant col- 

 lected by E. W. Nelson and E. A. Goldman in Lower California, 

 which bloomed at the New York Botanical Garden in April 1914. 

 Figure 83 represents a joint of a plant sent from La Mortola, 

 Italy, in 1912; figure 84 is from a photograph of this plant. 



Of this relationship, but of very different habit, is the species 

 collected by Dr. Rose on West San Benito Island in 1911. Unfor- 

 tunately no flowers or fruits could be obtained, and hence we have 

 not named it here. It may be briefly characterized as follows: 



OPUNTIA sp. 



Low, much branched plants; joints short (10 cm. long), thick, and 

 fleshy; leaves cylindric, 10 mm. long, acute; areoles distant, circular, 

 bearing brown wool, tawny glochids and numerous spines; spines 6 to 

 8, often 4 cm. long, slender, reddish brown, inclosed in loose, thin, brownish 

 sheaths. Collected by Dr. J. N. Rose on West San Benito Island, off 

 the west coast of Lower California, March 9, 1911 (No. 16043). 



33. Opuntia alcahes Weber, Bull. Mus. Hist. Nat. Paris i: 321. 1895. 



Plant about i meter high, much branched, very spiny, especially when FIG. 83 .-Opuntia prolifera 

 old; branches terete; spines on young joints about 12, short, covered with 



white or very pale sheaths; tubercles prominent, diamond-shaped; leaves small, i cm. long, terete, 

 somewhat bronzed; sepals small, brownish, closely imbricated, hardly spreading at tips' petals 

 sometimes wanting, or, if present, about i cm. long, greenish yellow, obtuse; stamens numerous- 

 stigma-lobes very short, 6 to 8, at first exserted beyond the sepals, yellowish; fruit globular' 

 small, becoming turgid in age, yellowish, more or less proliferous, the umbilicus truncated or 

 slightly depressed. 



Type locality: In Lower California. 

 Distribution: Lower California. 



