112 



THE CACTACEAE. 



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

 Cactus triacatitlws 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 usually 3, white but often drying yellowish, 4 cm. long or less; flowers, including the 

 ovaries, 5 cm. long, brownish yellow 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. 



FIG. 138. Opuntia bella. Xo.75. 



FIG. 139. Opuntia bella. Xo.66. 



When 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 cultivation in 1796. 



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

 is never found very far inland in the Lesser Antilles. 



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

 one in the Strc ptacanthac , 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 synonym of 0. curassavica, which is erroneous if our interpretation of 

 it is correct. 



Plate xvin, 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. Russell in 1913. 



