OPUNTIA. 



53 



9. Opuntia tetracantha Tourney, Card, and For. 9: 432. 1896. 



Low bush, 5 to 15 dm. high, branching; central stem woody, 5 to 8 cm. in diameter; young 

 joints 23 to 30 cm. long, 10 to 15 mm. in diameter, purplish; tubercles at first prominent, elongated, 

 1 6 to 22 rani, long; areoles bearing wool, light brown glochids, prominent glands and spines; spines 

 3 to 6, usually 4, slender, somewhat deflexed, 2 to 3.5 cm. long; flowers greenish purple, 1.5 to 2 cm. 

 broad; fruit 2 to 2.5 cm. ong, yellowish orange to "scarlet," nearly smooth, but rarely bearing a few 

 spines, deeply umbilicate; seeds 3 to 5 cm. broad, with irregular faces and a thick, spongy commissure. 



Type locality: Five miles east of Tucson, Arizona. 



Distribution: Known only from the region about Tucson, Arizona. 



The species was originally compared by Mr. Tourney with 0. thurbcri, with which he 

 thought it to be closely associated, but differing in "its longer, more strongly deflexed spines, 

 smaller and different-colored flowers." 



The type specimen was not indicated, but Tourney's own plant, collected in 1895, which 

 was recently purchased by the U. S. National Herbarium, is doubtless the type. 



Illustration: Bull. Torr. Club 32 : pi. 9, f. 2. 



Plate ix, figure i, shows a joint painted by L. C. C. Kriegeratthe Desert Botanical 

 Laboratory, Tucson, Arizona. 



10. Opuntia recondita Griffiths, Monatsschr. Kakteenk. 23: 131. 1913. 



"A stout broad-branched shrub, i to 1.5 meters in height; trunk cylindric, 4 to 7 cm. in diam- 

 eter, with constrictions corresponding to each year's growth, with gray bark, and having a few lateral, 

 easily detachable, weakly spined joints about 10 cm. long, the remaining joints being 20 to 30 cm. 

 long, very spiny, in the second year about 2 cm. in diameter, tuberculate; tubercles forming a ridge, 

 flattening out below, above extending precipitously, about 2 to 5 cm. long, 5 to 6 mm. wide, and 4 

 to 5 mm. high, remaining recognizable three years, and then disappearing; areoles broadly obovate, 

 5 to 6 mm. in the longest diameter, in age becoming larger and more prominent, forming new wool 

 for several years; glochids yellow, in a thick 3 mm. long 

 cluster on the upper part of the areole, also smaller clusters 

 on the other parts of the areole, mostly at the base of the 

 longest and most central spine; spines first 2 to 4, later 6 to 

 8 or 10, upr ght, spreading, 2,5 to 5 cm. long, in cross-sec- 

 tion weakly circular, gray at the base, becoming deep red- 

 dish brown at the tips, surrounded the entire length by a 

 loose, comparatively bright sheath; between the spines are 

 scattered a few dirty-black, sheathless bristles about 6 mm. 

 long; leaves subulate, finely tipped, terete, 12 to 20 mm. long. 



"Flowers bright purple, when open about 2.5 cm. in 

 diameter; petals finely and irregularly serrate, inconspic- 

 uously but finely irregularly notched; sepals thick, trian- 

 gular pointed, greenish purple; anthers greenish with purple 

 tinge; pistil greenish at base, with purple tinge above; 

 stigma-lobes 6, white; ovary obovoid, tuberculate, with small 

 areoles, 2 mm. in diameter, short greenish brown glochids 

 i to 2 mm. long, and i, 2, or 3 brown, caducous spines 

 sheathed in part; fruit not deciduous, 3 to 3.5 by 2 to 2.4 

 cm., large, greenish yellow with a reddish tinge on the outer- 

 most side, only weakly tuberculate in the second year, with 

 projecting brownish glochids 3 mm. long; seeds white, thick, 

 mostly flat but often lightly angled with narrowly thickened 

 edges, and often somewhat concave. " 



Type locality: La Perla, Mexico. 



Distribution: Known only from type locality, and, 

 to us, only from the description of which the above 

 is a translation by Mr. Russell. 



11. Opuntia thurberi Engelmann, Proc. Amer. Acad. 3:308. 1856. 



Large bushy plants, 2 to 4 meters high; joints slender, elongated, 1.5 to 2.5 dm. long, 10 to 12 

 cm. in diameter; tubercles 1.5 to 2 cm. long, flattened laterally; leaves linear, 6 to 8 mm. long, spread- 



FIG. 63. Opuntia tluirberi. Natural size. 



