64 



THE CACTACEAE. 



Opuntia imbricala ramosior Salm-Dyck, Cact. Hort. Dyck. 1849. 73. 1850. 

 Opunlia imbricala teniiior Salm-Dyck, Cact. Hort. Dyck. 1849. 73. 1850. 

 Opuntia vexans Griffiths, Rep. Mo. Bot. Gard. 22: 28. 1912. 

 Opuntia magna Griffiths, Proc. Biol. Soc. Washington 27: 23. 1914. 

 Opuntia spinotecla Griffiths, Proc. Biol. Soc. Washington 27: 24. 1914. 



Tree-like, often 3 meters high or higher, with a more or less definite woody trunk 2.5 cm. in 

 diameter; ultimate joints 2 to 3 cm. in diameter, strongly tuberculate; leaves 8 to 24 mm. long, 

 terete; tubercles 2 to 2.5 cm. long, flattened laterally; spines 8 to 30, 2 to 3 cm. long, brown, covered 

 with papery sheaths; flowers borne at ends of branches, 4 to 6 cm. long, sometimes 8 to 9 cm. broad, 

 purple ; ovary tuberculate, bearing a few bristles from some of the upper areoles ; fruit naked, yellow, 

 2.5 to 3 cm. long, strongly tuberculate or, when long persistent, smooth; seeds 2.5 to 3.5 mm. in 

 diameter. 



Type locality: Unknown; introduced into England by Loddiges in 1820. 



Distribution: Central Colorado to Texas, New Mexico, and central Mexico. 



The plant is hardy in southwestern Kansas, and has been recorded as a native of 

 that State ; it has existed through three winters out of doors at the New York Botanical 

 Garden, but has made little growth. 



We have followed Schumann and Weber in uniting Opuntia arborescens and 0. imbri- 

 cata. As thus treated, the species has a wide geographic distribution, and in our view 

 con sists of many slightly differing races. In its northern limits it is much smaller than in 

 its southern range. 



Opuntia cristata tenuior Salm-Dyck (Cact. Hort. Dyck. 1844. 49. 1845, name only), 

 0. decipiens major Hort. in Salm-Dyck (Cact. Hort. Dyck. 1844. 49. 1845, as synonym), 0. 

 cristata Salm-Dyck (Cact. Hort. Dyck. 50. 1842), and 0. stellata Salm-Dyck (Cact. Hort. 

 Dyck. 50. 1842) are unpublished names. 0. ruthei is a garden name mentioned by Berger. 



Opuntia cxuviata major (Salm-Dyck, Cact. Hort. Dyck. 1844. 49. 1845) is an unpub- 

 lished name. 



Opuntia cardcnche Griffiths (Rep. Mo. Bot. Gard. 19: 259. pi. 21, in part. 1908) is 

 described as standing between Opuntia kleiniae and 0. imbricala, being stouter than the 



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Fig. 79. — Opuntia imbricata. 



