1 66 the; cactaceae. 



Usuallv erect, 2 to 4 meters high, with a more or less definite trunk, but at times much lower and 

 spreading; joints green or bluish green, somewhat glaucous, orbicular to obovate, up to 25 dm. long; 

 leaves subulate, 3 to 4 mm. long, somewhat flattened, pointed; areoles distant, often 6 cm. apart; 

 spines usuallv i to 6, often only 2, one porrect and 4 cm. long or more, the others somewhat shorter 

 and only slig'htlv spreading, pale 3'ellow to nearly white, sometimes brownish or blackish at base, 

 or some' plants spineless; glochids yellow or sometimes brownish, usually prominent; petals yellow 

 to dark red; stigma-lobes usually green; fruit purple, pyriform to oblong, 2. 5 to 5.5 cm. long. 



Type locality: About New Braunfels, Texas. 



Distribution: Southwestern Louisiana, southeastern Texas, and Tamaulipas, Mexico. 



Opuntia lindheimeri is an extremely variable species, composed of many races, differing 

 in armament, color of flowers, size and shape of joints and of fruit. Certain forms have 

 been described which in cultivation we have been able to recognize as possibly distinct; 

 but in the field they seem to intergrade with other forms, indicating that they are at most 

 onlv races of a ver\' variable species. In the delta of the Rio Grande this is especiall)- true, 

 and from this region a number of species has been described. In fact, all the plants 

 described as species which are cited above in the sj.Tionymy grow within a relatively smaU 

 distributional area. Dr. Rose has examined all this region and is of the opinion that only 

 one species of this series exists there, and this we believe is to be referred to Opuntia lind- 

 heimeri. It is very common about Browns^-ille and Corpus Christi, where it forms thickets 

 covering thousands of acres of land. It is verj- variable in habit, being either lo\v and widely 

 spreading or becoming tall and tree-Hke, sometimes 3 meters high, with a definite cylin- 

 dric trunk. Plants from these two extremes, if studied apart from the field, might be con- 

 sidered as different species, but in the field one sees innumerable intergrading forms. The 

 low, prostrate forms gradually pass into others with more or less erect or ascending branches, 

 while the large tree-Hke forms often bear large lateral branches which lie prostrate on the 

 ground, indicating that they have developed from the prostrate ones. Decided differences 

 in the flower colors have been pointed out in the original descriptions, and we have obser^-ed 

 them in greenhouse specimens, but they do not correlate with other characters. 



Opuntia ellisiana Griffiths (Rep. 'Mo. Bot. Gard. 21: 170. pi. 25. 1910), an unarmed 

 species, is known only from cultivated plants. Dr. Griffiths states that it is quite different 

 from the Ficus-indicae series, which it much resembles, and is quite hardy in southern Texas. 

 It may be a spineless race of the common 0. lindheimeri of this region. 



Opuntia pyrocarpa Griffiths (BuU. Torr. Club 43: 90. 19 16) we do not know; in its 

 long pjTiform fruit it suggests this plant; the type comes from ^Marble Falls, Texas. 



0. 'ix'interiana Berger and 0. haematocarpa Berger (Bot. Jahrb. Engler 36:455 and 

 456. 1905) are of this relationship, but have browner spines than is usual in the species. 



Opuntia leptocarpa ^Nlackensen (BuU. Torr. Club 38: 141. 1911), characterized b}- its 

 low, bushy habit and elongated, almost abnormal fruits, suggests a natural hybrid between 

 0. lindheimeri and 0. macrorhiza. Indeed, Mr. :Mackensen described the species as inter- 

 mediate between these two, and aU three species are often found growing together. 0. 

 leptocarpa originally came from San Antonio, Texas. 



Illustrations: Ann. Rep. Smiths. Inst. 1911: pi. 3, 4, B; Cact. Mex. Bound, pi. 75, f. 

 5 to 7; Karsten, Deutsch. Fl. f. 501. 13, 13^, 13b; N. Mex. Agr. Exp. Sta. Bull. 78: pi. [13, 

 14], aU as Opuntia dulcis. Bull. U. S. Dept. Agr. 31: pi. 3, f. i, this as Opuntia cacanapa; 

 Rep. Mo. Bot. Gard. 20: pi. 4, in part, this as Opuntia tricolor; Rep. Mo. Bot. Gard. 20: 

 pi. 9; pi. 13, f. I, these two as Opuntia texana. BuU. U. S. Dept. Agr. 31: pi. 2, f. i ; Rep. 

 :Mo. Bot. Gard. 20: pi. 2, f. i ; pi. 11 ; pi. 13, f. 4, aU these as Optuitia subarmata. Rep. Mo. 

 Bot. Gard. 21: pi. 19; pi. 20, in part, these two as Opuntia alta. Rep. Mo. Bot. Gard. 

 21: pi. 21 ; pi. 22, in part, these two as Opuntia gomei. Rep. Mo. Bot. Gard. 21: pi. 28, this 

 as Opuntia sinclairii. Rep. Mo. Bot. Gard. 22: pi. 9, in part; pi. 10; Joum. Agr. Research 

 4. pi. f., these three as Opuntia cyanella. Rep. INIo. Bot. Gard. 22: pi. 9, in part; pi. 16, 

 17, these three as Opuntia gikoalba. BuU. U. S. Dept. Agr. 31: f. i. . 



