I02 the; cactaceae. 



Collected by Dr. and Mrs. J. N. Rose in central and southern Peru, in 1914, first from 

 just below Matucana (No. 18653), and later at Pasco (No. 188 12, type). 



Plate XVII, figure i, represents a joint of the type specimen above cited. 

 Series 2. CURASSAVICAE. 



This series is composed of 10, or perhaps 11, species of low plants, characterized by their fragile 

 branches, the small joints separating and becoming detached very readily, more or less flattened or 

 subterete. They mostly inhabit the southern United States and the West Indies ; one is known 

 from Ecuador; the original home of one of the species recognized is unknown. 



Key to Species. 



Spines acicidar. 



Joints oval, mostly not more than twice as long as wide; plants prostrate, little branched So. 0. curassavica 



Joints oblong to Unear, 2 to 8 times as long as wide; plants ascending or erect, much branched. 



Joints narrowly linear, i to 2 cm. wide 81. 0. taylori 



Joints oblong to linear-oblong or obovate-oblong, 2 to 4 cm. wide. 



Joints oblong to Unear, 4 to 8 times as long as wide; spines i to 3 cm. long. 



Joints not tubercled 82. 0. repens 



Joints tubercled, at least when young 82a.. O. pestifer 



Joints oblong to obovate-oblong, 2 to 3 times as long as wide; spines 3 to 5 cm. long 83. 0. borinquensis 



Spines subulate. 

 Spines white. 



Roots fibrous; spines at most of the areoles 84. 0. militaris 



Roots tuberous; spines only at the upper areoles 85. 0. nemoralis 



Spines brown. 



Joints oval to oblong. 



Joints scarcely repand; plant up to 2 dm 86. O. drummondii 



Joints strongly repand; plant i dm 87. O. tracyi 



Joints linear-lanceolate 88. 0. pusilla 



Affinity uncertain 89. 0. darraUana 



80. Opuntia curassavica (Linnaeus) Miller, Gard. Diet. ed. 8. No. 7. 1768. 



Cactus curassavicus Linnaeus, Sp. PI. 469. I753- 



Stems low, 5-jointed, light green, pros- 

 trate and creeping or hanging over rocks ; joints 

 oval to oblong, decidedly flattened but thick, 

 2 to 5 cm. long, glabrous ; leaves minute, soon 

 withering; areoles small, bearing short wool ,^ T^f^^^^r '' 



and longer, white cobwebby hairs ; spines 4 to '^^^^C<^'iS>i^^^^^S^I'^^^i'''M^^^^'^ ^ 



many, acicular, 2.5 cm. long or less, yellowish, -"^^ "" 



becoming white in age; glochids tardily de- 

 veloping. 



V Type locality: CuragaO Island. Fig. 125.— Opuntia curassavica. Xo.75- 



Distribution: Curagao, Bonaire, and Aruba. 



Haworth (Syn. PI. Succ. 196. 1812) describes three varieties, major, media, and minor, 

 and later (Rev. PI. Succ. 71. 1821) also describes the variety longa. 0. curassavica elongata 

 Haworth (Salm-Dyck, Hort. Dyck. 184. 1834), a name only, is supposed to be the same 

 as var. longa. 



This is one of the oldest species of Opuntia, having been described and figured as early 

 as 1696. For a long time it has been unknown, the name having been transferred to a 

 similar species, 0. repens. In 1913 Dr. Britton visited Curasao, its native home, and re-col- 

 lected it. Its flowers have not been described, and several residents informed him that 

 they had never seen it in flower; Dr. Britton did not find it in flower on Curagao, nor has it 

 flowered with us in cultivation; Haworth, who wrote about it in 1812, speaks of its being 

 a shy bloomer, saying he had seen it in flower but once. In early English books it is called 

 pin pillow, because its turgid joints suggest pincushions filled with pins. 



Illustrations: Bradley, Hist. Succ. PI. ed. 2. pi. 4, as Opuntia minima americana, etc.; 

 Commerson Hort. pi. 56, as Opuntia curassavica minima; Plukenet, Opera Bot. 3: pi. 281, 

 f. 3, as Opuntia minor caulescens. 



Figure 125 represents the plant collected on Curagao by Dr. N. L. Britton and Dr. 

 J. A. Shafer in 1913. 



