162 



THE CACTACEAE. 



Australia. J. H. Maiden says: "The growth of this Opuntia is one of the wonders of the 

 world, and the spread of few plants in any country can be compared with it. " 



Illustrations: Dept. Agr. N. S. W. Misc. Publ. 253: pi. [5]; Card. Chron. III. 34: f. 32; 

 Gartenflora 31: pi. 1082, f. d, e, f ; De Candolle, PI. Succ. Hist. 2: pi. 138 [C]; De Tussac, Fl. 

 Antill. 2: pi. 34, the last two as Cactus opuntia inermis; Agr. Gaz. N. S. W. 23: pi. opp. 713 ; 

 pi. opp. 714; pi. opp. 716; Bliihende Kakteen 2: pi. 108, all these as Opuntia inermis. 



Plate xxvn, figure 4, represents a flowering joint of the plant collected by Dr. Brit- 

 ton and John F. Cowell on limestone rocks near Pinar del Rio, Cuba, in 191 1. 

 173a. Opuntia keyensis Britton. (See Appendix, p. 222.) 



174. Opuntia dillenii (Ker-Gawler) Haworth, Suppl. PL Succ. 79. 1819. 

 Cactus dillenii Ker-Gawler, Edwards 's Bot. Reg. 3: pi. 255. 1818. 

 Opittitia liorrida Salm-Dyck in De Candolle, Prodr. 3: 472. 1828. 

 Opuntia maritime Rafinesque, Atl. Journ. 146. 1832. 

 Opuntia tnnoidea Gibbes, Proc. Elliott Soc. Nat. Hist, i: 272. 1859. 



FIG. 201. Opuntia dillenii, Antigua. West Indies. 



Low, spreading bushes growing in broad clumps and often forming dense thickets, or tall and 

 much branched, 2 to 3 meters high, sometimes with definite terete trunks; joints obovate to oblong, 

 7 to 40 cm. long, the margin more or less undulate, bluish green, somewhat glaucous, but bright 

 green when young, the areoles somewhat elevated; leaves subulate, curved backward, 5 mm. long; 

 areoles often large, filled with short brown or white wool when young, usually few and remote, on 

 old joints 10 to 12 mm. in diameter; spines often 10 from an areole on first-year joints, very variable, 

 usually more or less flattened and curved, sometimes terete and straight, yellow, more or less brown- 

 banded, or mottled, often brownish in age, sometimes 7 cm. long, but usually shorter, sometimes few 

 or none; glochids numerous, yellow; wool in areoles short, sometimes brown, sometimes white; 

 flowers in the typical form lemon-yellow, in some forms red from the first, 7 to 8 cm. long; petals 

 broadly obovate, 4 to 5 cm. long; filaments greenish yellow; style thick, white; stigma-lobes white; 

 fruit pear-shaped to subglobose, narrowed at base, 5 to 7.5 cm. long, purplish, spineless, juicy. 



Type locality: Based on Dillenius's illustration. 



Distribution: Coasts of South Carolina, Florida, Bermuda, the West Indies, east coast 

 of Mexico, and northern South America; extending inland in Cuba. 



