170 MISSOURI BOTANICAL GARDEN. 





monly 3 to 4 or more meters high, in cultivation plants have made a 

 12-dm. growth in 2 years from single joint cuttings; joints obovate, 

 broadly rounded above, about 17 by 25 cm., papillate-pubescent under 

 a lens, this scarcely detected by touch except in current season's 

 growth, deep dark green, with young growth of course lighter in color; 

 areoles at first brown turning dirty black, broadly oval to sub-circular 

 or even obovate, about 5 mm. in longest diameter, 2 to 2i cm! apart; 

 leaves short, subulate, cuspidate, mostly only 3 mm. in length; spic- 

 ules brown, in hemispherical bunches in upper part of areole, 2 to 3 

 mm. long at first, but developing anew from lower central portion of 

 spicular area to often 1 cm. in length, this new development continuing 

 for a couple of years; spines white, turning to a dirty gray, not very 

 stout, but resembling those of O. chavena, but longer, numerous, 

 erect, spreading in all directions, 4 to 6 on last year's joints, but be- 

 coming very numerous in places on old trunks, even 25 to 30, varying 

 in some areoles from 15 to 25 mm. in length; besides spines and spic- 

 ules, current year's joints bear two delicate, hairlike, fugacious 

 spines, about 5 mm. long; fruit small, about 3X3.5 cm. purplish red, 

 with pulp deeper in color and seeds easily separable. 



The species is one of the tree forms of the highland of 

 Mexico of the southern Zacatecas and Aguas Calientes 

 region. It is very different from any other species with 

 which I am familiar, especially in size of fruit. My field 

 notes indicate that when it was collected it was thought to 

 belong to the 0. chavena group. Its brownish red spicules, 

 however, make it appear quite different and its fruits are 

 entirely different. It has been seen in cultivation in sev- 

 eral localities and apparently native to the vicinity of Aguas 

 Calientes. 



The description was drawn in the main from a cultivated 

 specimen in the third year of its growth from a single joint 

 cutting, amended by notes from the type and other localities 

 in Mexico. No flowers of it have been seen. The type 

 specimen is one bearing my collection No. 8138, prepared 

 from a cultivated specimen which was collected under the 

 same number near Aguas Calientes, Mexico, September 16, 

 1905.— Plate 24. 



Opuntia Ellisiana sp. nov. 



Plant spreading, ascending, laxly branched, 10 to 14 cm. high and 

 14 to 20 dm. in diameter, depending upon moisture and fertility con- 

 ditions; joints light glaucous blue-green, obovate or ovate, about 20 



