4 The cactaceae. 



The generic name is from ayKtarpov fish-hook, and kclktos cactus, referring to the 

 -long, hooked central spines. 



Ancisirocactus was used by Schumarm for a subgenus of Echinocactus. We recognize 

 three species in the genus, occiuring in southern Texas and northern Mexico. 



Coulter (Contr. U. S. Nat. Herb. 3: 368, 369) calls attention to grooved areoles of 

 Echinocactus brevihamahis resembling those of Coryphantha and Echinocactus scheeri. 



Key to Species. 



Radial spines 20 or more, strongly appressed, pectinate; flowering areoles naked i. .-1. megarhizas 



Radial spines 1 8 or fewer, more or less spreading, hardly pectinate ; flowering areoles woolly. 



Groove half length of tubercle: flower greenish; radial spines 15 to 18 2.-4. scheeri 



Groove extending full length of tubercle; flower rose-colored; radial spines usually 12 . 3.-4. breviliamalus 



1. Ancistrocactus megarhizus (Rose). 



Echinocactus megarhizus Rose, Contr. U. S. Nat. Herb. 12: 290. 1909. 

 Solitary or in clusters of 3 or 4 ; plant bod}^ nearly globular or a little elongated, 5 to 8 cm. high, 

 usually solitan.-, from large and flesh}' roots; ribs spiral, divided into dark-green tubercl-s, 4 to 5 



-ti^f^ 



3* ^Wl^'Wtesi 



Fig. I. — Ancistrocactus megarhizus. 



cm. high; radial spines 20 or more, pectinate, at first pale yellow, in age white; in seedlings the 

 spines pubescent; central spines usually 4, the 3 upper similar to the radials, although a little stouter 

 and in young areoles not easily distinguished from them, the lower central spines stout and strongly 

 hooked, 15 mm. long; flowers not seen; fruit green, suggesting that of a Coryphantha, clavate, bearing 

 a few naked scales near top ; seed black, smooth, shining. 



Type locality: Near Victoria, Mexico. 

 Distribution: Known only from the type locaHty. 



Text-figure i is from a photograph of the type specimen collected by Dr. Edward 

 Palmer. 



2. Ancistrocactus scheeri (Sakn-Dyck). 



Echinocactus scheeri* Saha-Dyck., Cact. Hort. Dyck. 1849. 155. 1850. 

 Globular to clavate, 3.5 to 5 cm. long; ribs usually 13, indistinct, somewhat spiraled, strongly 

 divided into stout, terete tubercles grooved only to middle; radial spines 15 to 18, spreading, 12 



* This name was originally spelled Echinocactus sclieerii. 



