CACTACEAE. 



255 



Corolla rotate, without a tube ; joints of the plant flat or cylindric ; day-floworing. 



1. Opuntia. 

 Corolla funnelform, with a long tube ; joints trigonous ; night-flower- 

 ing. 2. Ilylocercus. 



1. OPUNTIA Mill. 

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

 and small mostly subulate deciduous leaves, the areolae axillary, often 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 pear-shaped, often spiny. [Named from 

 a town in Greece where some species grew.] About 200 species, natives of 

 America. Type species : Cactus Opuntia L. 



1. Opuntia Dillenii (Ker.) Haw. 

 Prickly Pear. (Fig. 277.) Bushy- 

 branched, 14°-5° high, often forming 

 masses 6° in diameter. Joints green, 

 glabrous, mostly obovate and 5'-10' 

 long, about 4" thick, crenate, the 

 areoles I'-li' apart, somewhat ele- 

 vated, bearing 1-4 stout yellow 

 spines J'-li' long, or spineless, the 

 numerous glochides yellowish to 

 brownish, 3" long or less; flowers 

 solitary at the areoles, often abun- 

 dant, bright yellow, about 3' broad ; 

 ovary obovoid, with glochide-bearing 

 areoles; petals obovate; stamens 

 much shorter than the petals; fruit 

 pyrif orm, red-purple, edible, 2'-3' long. 

 [Cactus Dillenii Ker; Opuntia Tuna 

 of Lefroy, Jones, H. B. Small, Hems- 

 ley, Verrill and Moore; 0. vulgaris 

 of Eeade, Kemp, H. B. Small and 

 Harshberger; Cactus Opuntia of 

 Michaux.] 



Common in sandy soil near the coasts, and occasional on hillsides inland. 

 Native, Florida and the West Indies. Flowers in summer and autumn. The only 

 native cactus. In shade, the joints greatly elongate and are proportionately nar- 

 rower, sometimes 1° long and only 2Y wide, spineless, or nearly so. 



Opuntia pes-corvi LeConte, a low, brown-spined species of Georgia and 

 Florida, with small joints readily separating, is recorded as Bormudian by 

 Eein and Lefroy and admitted by Hemsley and by Verrill, in all probability 

 erroneously, as it has not been found by subsequent collectors. 



Opuntia tomentosa Salm-Dyck, Tall Velvety Prickly Pear, Mexican, is 

 grown for interest, attaining a height of 15°-20° with a roughish trunk up to 

 nearly a foot in diameter. A fine specimen existed in 1014, on a bank near the 

 roadside, approaching St. George's. The joints of this species are dull green 

 and finely velvety, and the flowers small and rose-colored. 



Opuntia Ficus-indica (L.) Mill., Tall Smooth Prickly Pear, tropical 

 American, with large, nearly or quite smooth and often spineless joints, is 

 occasionally grown; its oblong yellowish fruits are about 3' long. 



Opuntia leucotricha DC, Aaron's Beard, Mexican, a tall broad-jointed 

 species, covered with long, whitish stiff hairs, is occasionally planted for in- 

 terest. Fine specimens were seen at Whitehall and Caledonia Park, st 

 George's, in 1913. 



