198 TRANS. OF THE ACAD. OP SCIENCE. 



thus* the Mexican E. horripilus, Lera., and perhaps the South 

 American E. Odierii, Lera., and E. Cummingii, Salni, this 

 species forms a small section of Echinocacti with the appear- 

 ance of Mamillame, named by Prince Salm, (Hort. Dyck., 

 1849, p. 31,) Theloidei. Through the CoryphantJup they are 

 nearly allied to Mamillaria, while our species at least, (the 

 fructification of the others not being known,) by its dry fruit, 

 its black tuberculated seeds, and especially the large and 

 curved embryo and the presence of an albumen, proves it self 

 a true Echinocactus, very closely connected with the regu- 

 larly ribbed E. intertextus, Eng. Cact., Mex. Bound, t. 34. 

 The similarity in all essential organs of these two species is 

 such that no system ought to separate them, proving again of 

 how little essentia] importance among Cactacese the external 

 form must be regarded; another striking example, among 

 many, is the rat-tail Cereus tuberosus, and its globular or oval 

 allies, C. ccespitosus, etc. 



Full grown specimens are 3-5 inches high and 3-4 inches 

 in diameter ; dark green tubercles, loosely arranged in ^ r or 

 £f order, 8 and 13 spirals being most prominent ; tubercles 

 6-8 lines long, at base 6-7 1. wide in the vertical and 4-5 1. 

 in the transverse diameter, fruit-bearing ones rather shorter 

 and stouter; areola 3-4 1. long; external spines 4-6 1. long, 

 whitish, with the addition of several bristles at the upper end 

 of the areola ; central spines 5-7 1. long, yellow, reddish, deep 

 brown, or even black, upwards. Flowers 8-10 1. long, and of 

 nearly the same diameter, with a short and wide tube, exter- 

 nally greenish purple, petals yellowish-green verging to pale 

 purple; the short stamens arise from the whole inner surface 

 of the tube, leaving only a very small nectariferous space in 

 its base; funiculus very short, stout and straight, and not 

 curved over the micropyle, as I have found it in almost all 

 other cactus flowers examined. Fruit 3-3£ 1. long, about the 

 same in width, with 1-3 small calycine scales towards its flat 

 top, each with 1 or 2 small spines in its axil ; it usually bursts 

 irregularly on the side, and, falling off, leaves its base adher- 

 ing U> the areola, as is the case in other dry-fruited Echino- 

 cacti; e. g. E. liorizonthalonius. Seeds 1J 1. long in the 

 Longest diameter, covered with minute closely set tubercles, 

 with a large oval subbasilar hilum, and an embryo strongly 

 curved around a small albumen. The plant germinates with 



• Mamillaria ■papyracantha,Vng. PI. Fend]., p. 40; Syn. Cact., p. 8. A 

 closer examination of the dry specimen obtained by Mr. Fendler near 

 Santa Fe proves that the floral areola joins the spiniferoua one on the top 

 of the small nascent tubercles, making the plant an Echinocactus, accord- 

 in"- to the views at present prevalent. It is singular that Fendler's single 

 specimen has remained, thus far, the only one ever obtained of this well 

 marked species. 



