60 THE CACTACEAE. 



IvOBIVIA sp. 



Dr. Shafer collected many specimens of a plant at Villazon, Bolivia, in February 191 7 

 (No. 86), which may represent another species of this genus, but they were at that time 

 without flowers or fruit, and none has flowered since brought by him to the New York 

 Botanical Garden. 



This cactus is tufted, forming clumps 1 to 2 dm. broad; its joints are short-cylindric to turbinate, 

 8 to 15 cm. high and 5 to 7.5 cm. thick, 14 to 18-ribbed; areoles few in each rib, white-felted when 

 young, elliptic; spines 2 to 5, somewhat flattened and appressed, about 1 cm. long, white with black 

 tips. Dr. Shafer was told that its flowers are white. 



6. ECHINOPSIS Zuccarini, Abh. Bayer. Akad. Wiss. Miinchen 2:675. i837- 



Echinonyctanthus Leraaire, Cact. Gen. Nov. Sp. 10. 1839. 



Stems usually low, rarely over 3 dm. high, usually much shorter, generally globular or short- 

 cylindric, but some species large, columnar, either solitary or clustered, with ribs either continuous 

 or more or less undulate ; areoles usually circular, borne on the ribs, felted and spiny ; flowers arising 

 from old areoles just above the spine-clusters, with a very long narrowly funnelform tube; perianth- 

 segments comparatively short and broad, more or less spreading, usually white, rarely yellow or 

 rose-colored*; filaments and style projecting beyond the throat but not beyond the perianth- 

 segments; stamens in 2 series, weak; stigma-lobes of various colors, narrow; fruit globose to ovoid 

 or sometimes narrowly oblong, splitting open on one side ; seeds minute, oblique, obovate, truncate 

 at base. 



Echinocactus eyriesii Turpin is the type of the genus. 



The generic name is from exiws hedgehog, and 6<pis appearance, referring to the 

 armament of the plant. 



Some of the species have been taken up in Echinocactus or Echinonyctanthus, many in 

 Cereus, while one species, though excluded from Echinopsis in our treatment, has also been 

 referred to Cleistocactus and Pilocerens. 



In its flowers Echinopsis is like Trichocereus and somewhat like Harrisia, but in habit 

 it is abundantly distinct from these genera. In habit, although not in flowers, it seems 

 to be the South American counterpart of the North American genus Echinocercus. Gar- 

 deners and botanists generally have recognized it as a well-defined genus, but Bentham 

 and Hooker in their Genera Plantarum reduced it to Caeus, and their course has been 

 followed by some other English authors. While the genus as treated by Schumann contains 

 mostly species of low stature there are some striking diversities in flowers and we have conse- 

 quently segregated these under the generic names Lobivia and Rebutia. Schumann recog- 

 nized 18 species of this genus. Von Rother states that he had 55 forms growing in his 

 collection; some of these must have been hybrids of which there are many. We here 

 recognize 28 species, but further field observations may prove that this number should 

 be reduced. There are, however, more than 200 names published under Echinopsis to be 

 accounted for. The known species inhabit southern South America, east of the Andes. 



Key to Species. 



A. Tube of perianth distinctly longer than limb. 

 B. Flowers white to red or pinkish. 

 C. Spines all straight, subulate. 



Inner perianth-segments thread-like 1. E. meyeri 



Inner perianth-segments broad. 



Stems slender, cylindrie, much longer than thick. 



Fruit very slender 2. E. mirabilis 



Fruit (so far as known) globular. 



Flowers 10 cm. long 3. E. forbesii 



Flowers 17 to 20 cm. long. 



Central spines 1 to 4, 4 cm. long 4. E. huottii 



Central spine solitary, 5 to 6 cm. long 5. E. minuana 



"In Echinopsis aurea and E. formosa the flowers are yellow, in E. multiplex and E. oxygona red to rose. 



