THE CACTACEAE. 



100. Opuntia triacantha (Willdenow) Sweet, Hort. Brit. 172. 1826. 

 Cactus triacantlws Willdenow, Enum. PI. Suppl. 34. 1813. 



Stems half procumbent or clambering over rocks, sometimes even erect but always low; joints 

 turgid, oblong, 4 to 8 cm. long, the terminal and often the second and third ones breaking off 

 easily; spines usualh' 3, white but often dn,-ing yeUo^rish, 4 cm. long or less; iiowers, including the 

 ovaries, 5 cm. long, brownish j-eUow to cream-colored, tinged with pink ; petals obtuse ; filaments and 

 style pale green; fruit 2.5 cm. long, red, spineless. 



Type locality: Not cited; cultivated in the Berlin Garden. 



Distribution: Desecheo Island, Porto Rico; Lesser Antilles, St. Thomas to Guadeloupe. 



Opuntia bella. Xo.66. 



^^"hen published, the origin of this species was uncertain. It has been referred to the 

 South American flora, but if our interpretation is correct it is a West Indian plant. It was 

 introduced into ctdtivation in 1796. 



This species is ver\^ common on flats or low hills and, so far as our observation goes, 

 is never found verj^ far inland in the Lesser Antilles. 



Professor Schumann's description includes two species, one of which belongs here and 

 one in the Streptacanthae, perhaps as Mr. Berger thinks to 0. amydaea — and a tall plant, 

 3.5 meters high, is now grown in Italy under that name. The Index Kewensis refers 

 0. triacantha as a s>Tionym of 0. curassavica, which is erroneous if our interpretation of 

 it is correct. 



Plate x^^II, figure 3, represents joints of the plant collected on Antigua by Rose, Fitch, 

 and Russell in 1913. Figure 140 is from a photograph taken on St. Christopher, British West 

 Indies, by Paul G. RusseU in 1913. 



