64 THE CACTACEAE. 



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

 Opuntia imbricata teiniior Salm-Dyck, Cact. Hort. Dyck. 1849. 73. 1850. 

 Opunlia vcxans Griffiths, Rep. Mo. Bot. Card. 22: 28. 1912. 

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

 Opuntia spinotecta 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 L,oddiges 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 arborcsccns and 0. inibri- 

 chta. 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 tcninor Salrn-Dyck (Cact. Hort. Dyck. 1844. 49. 1845, name only), 

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

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

 Dyck. 50. 1842) are unpublished names. 0.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



Opunlia cxitriata 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 Opnniia klciniac and (>. imbricata, being stouter than the 



FIG. 79. Opuntia imbricata. 



