CACTACEAE. 295 



is often hidden between the tubercles. Petals in several rows. Ovary smooth, 

 ovoid; style filiform. Berry emersed, crowned by the withering corolla. 

 [Greek name of some prickly plant,] About 300 described species, natives of 

 warm and tropical America. Type species: MammiUaria svlcolanata Lemaire. 



1. Coryphantha nivosa (Link.) Britton, Annals Mo. Bot. Gard. 2: 45. 1915. 



MammiUaria nivosa Link; Pfeiff. Enuni. 11. 1837, 



Plants globose or globose-oblong, solitary or tufted, becoming 10-12 cm. 

 in diameter, and sometimes 1.5 dm. long. Tubercles many, dull green, oblong- 

 conic, 1-1.5 cm. high, obtuse; areoles bearing several yellow or yellowish brown, 

 acicular spines 2 cm, long or less, and when young, tufts of bright white wool; 

 flowers cream-color, about 1 cm. broad; perianth-segments acute or acuminate; 

 berry obovoid or o'blong-obovoid, obtuse, 1-1.5 cm. long, red. Woolly Nipple- 

 cactus. 



Rocky places, South Cnicos and Inagua : — Mona ; Culebra to Tortola and Antigua. 

 Recorded by Dolley as Echinocactus sp. 



7. OPUNTIA [Tourn.] Mill. Gard. Diet. Abr. ed. 4. 1754. 



Succulent plants, with jointed branching stems, the joints flat, or cylindric, 

 and small, mostly subulate, deciduous leaves, the areolae usually spine-bearing. 

 Flowers usually lateral. Calyx-tube not prolonged beyond the ovary, its lobes 

 spreading. Petals numerous?, slightly united at the base. Stamens very 

 numerous. Ovary cylindric, exserted; style cylindric, longer than the stamens; 

 stigma 2-7-rayed, Berry globose to obovoid, often spiny. [Named from a 

 town in Greece where some species grew.] About 250 species, natives of 

 America. Type species: Cactus Opuntia L. 



Plants with erect continuous stems branching into flat joints at the summit. 

 Plants abundantly spiny. 



Branches erect or ascending; areoles not pitted. 1. O.yashii. 



Branches widely spreading ; areoles pitted, spineless ex- 

 cept at and near the edges of the joints. 2. O. Milhpnuphii. 

 Plants nearly or quite spineless. o. (>. buhamana. 

 Plants bushy-branching from the base. 



-Toints much longer than wide, the spines pale yellow. 4. O. Iiicai/aua. 



Joints little or somewhat longer than wide ; spines dark 



yellow or yellow-brown. ">. O. Dillcnii. 



Affinity uncertain. 0. O. Dnrrahinna. 



1. Opuntia Nashii Britton, Bull. N. Y. Bot. Gar.l. 3: 446. 1005. 



Tree-like, dull green. Main axis round, 1—4 m. high, 5-12 cm. in diameter, 

 spiny; branches flat or becoming round below, the principal ones continuous, 

 1 m. long or more^ 6 cm. wide or less, crenate, blunt ; lateral branches opposite 

 or alternate, oblong to linear-oblong, often 3 dm. long, and 8 cm. wide, only 

 about 6 mm. thick, blunt, crenate; areoles 1-3 cm. apart, slightly elevate. 1 ; 

 spines mostly 5 at each arcole (2-5), divergent, slender, straight, light gray, 

 pungent, the longer 3-5 cm. long; glochides very small, brownish; ovary W cm. 

 long, 1.5 cm. thick, somewhat clavate. tultercleil, the tubercles bearing areoles 

 and spines similar to those of the joints, but the si>inos somewhat shorter; 

 flowers 1.5 cm. broad when expanded, red ; petals broadly oval to obovate, 

 blunt, about 8 mm. long, much longer than the stamens. 



Scrub-lands and rockv plains. Andros. Ship ChaniiPl Cay. Atwood Cny, Fortuno 

 Island. Crooked Island. North and South Calcos. Grand Turk. Kastorn Cay. Turk's 

 Islands and Inagua. Endemic. Recorded by Mrs. Northrop nnd l)y Hitchcock n.s 

 Opicntia spino.sissima : and by Coker and presumably by Dolley ns O. triarontha. 

 Nash's Prickly-pear. 



