OPUNTIA. 



209 



Figure 263 is from a photograph of the plant taken by Professor John F. Cowell at 

 Guanica, Porto Rico, in 1915; figure 264 is from a photograph taken by Professor Cowell 

 at the same time and place, showing in the foreground a mass of young plants arisen 

 from proliferating joints, and a mature plant behind; figure 265 represents proliferating 

 joints of a plant grown at Nisky, St. Thomas, collected by Dr. Britton and Dr. Rose 

 in 1913; figure 266 represents a fruit, collected by Dr. Britton and Dr. Shafer on Buck 

 Island, St. Thomas, in 1913. 



Figs. 265. 266.— Opuntia rubescens. X0.66. Fig. 267.— Opuntia brasiliensis. X0.75. 



Series 27. BRASILIENSES. 



This series represents one of the five subgenera described by Dr. Schumann, which he called 

 BrasiUopuntia. It perhaps should be recognized as a distinct genus. We recognize three species in 

 the series, which may be races of a single one, characterized by an erect cylindric trunk with cylin- 

 dric, horizontal branches terminating in a series of flattened, thin, leaf-like branches. The 

 leaves are small and caducous. The spines are few on the young growth, but large clusters are 

 developed on the old stem and trunk. The flowers are small, the fruit is juicy, and the seeds are 

 large and covered with a dense mass of wool. Unlike most species of Opuntia, these grow 

 in the moist tropical forests, forming tall, slender, tree-like plants. 



Key to Species. 



Fruit globular, yellow 236. O. brasiliensis 



Fruit clavate to oblong, red. ' ^ , , • 



Fruit oblong, 3 to 4 cm. long 237- 0. hahiensis 



Fruit clavate, 5 cm. long 238. 0. argenhna 



236. Opuntia brasiliensis (Willdenow) Haworth, Suppl. PI. Succ. 79. 1819. 



Cactus brasiliensis Willdenow, Enum. PI. Suppl. 33. 1813. 

 Cactus paradoxus Homemann, Hort. Hafn. 2: 443. 1815. 

 Cactus arboreus Vellozo, Fl. Flum. 207. 1825. 

 Opuntia arborea Steudel, Nom. ed. 2. 2: 220. 1841. 

 Cereus paradoxus Steudel, Nom. ed. 2. i: 335. 1841. 



Becoming 4 meters high, with a cyhndric woody trunk and a small rounded top; old trunk 

 either naked or spiny; branches dimorphic, the lateral ones horizontal, terete; the terminal joints 

 flat and leaf -like, many of these in time dropping off; flowers 5 to 5.5 cm. long; petals yellow, oblong, 

 obtuse ; filaments very short; fruit yellow, globular, 3 to 4 cm. in diameter, with a low or nearly trun- 

 cate umbilicus, bearing large areoles; seed usually one, very woolly, 10 mm. broad. 



Type locality: Near Rio de Janeiro, Brazil. 



Distribution: Southern Brazil, Paraguay, Argentina, and central BoHvia. Natural- 

 ized in southern Florida. 



