OPUNTIA. 



53 



tetracantha 



1896. 



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

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

 16 to 22 mm. 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 onlv from the redon about Tucson. Arizona. 



compared by Mr. Tourney 



more 



smaller 



specimen was not indicated, but Toumey's o\ 

 Durchased bv the U. S, National Herbarium 



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



Laboratory 



figure I, shows a joint painted by L 



recondita Griffiths. Monatsschr 



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 h 

 Distrib 



La Perla, Mexico 

 Known onlv from 1 



from 



the above 



Mr 



Fig. 63. — Opuntia tluirbcri. Natural size 



11. Opuntia thurberi Engel 



Proc. Amer. Acad. 3:308. 1856. 



Urge 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 Imear, 6 to 8 mm. long, spread- 



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