20. CACTACE^. 



65 



Citr-ullus vulgaris. 



rough above, hairy below, pahii- 

 ately cut into 3 broad, sinuate 

 lobes, the terminal lobe the 

 longest and pinnatifid ; petioles 

 stout, villous, nearly as long as 

 the leaves ; flowers solitary, 

 axillary, stalked : calyx villous, 

 with linear-lanceolate teeth as 

 long as the tube ; corolla yellow- 

 ish, downy, 25 - 35 mm. (over 1 

 in.) across; filaments free; ovary 

 silky-villous ; fruit globular or 

 oblong 7-15 cm. (3-6 in.) diameter, 

 glabrous, smooth, green-striped, 

 mottled with whife, or all yellow: 

 flesh bitter or sweet. 



Sandy land, cultivated or un- 

 cultivated. This is the Water- 

 melon or PicmeJon gone wild. — 

 Jan. -Mar. — Africa. 



Crassukt tetrcu/ona. L., a 

 succulent branching perennial, 

 has been -found localised near 

 Happy Valley as a garden 

 escape. Leaves subcylindrical, 



acute, flattish above and somewhat 3-angled or 4-angled 

 in section, 20-25 mm. long, opposite and each pair at right 

 angles to the next; flowers small, white, in corymbose 

 panicles ; sepals, petals, stamens and carpels 5. — Nov. -Dec. — • 

 South Africa. The family of the Crassulacecc has fleshy 

 leaves and stems like Ficoidacece, but the fruit is dry, free, 

 and consists of several distinct carpels. 



Family 20.— CACTACE/E. 



1. Opuntia, DC. 

 Sepals and petals numerous, overlapping; stamens 

 numerous; style 1, with several stigmas; stems composed of 

 fleshy, superimposed, leaflike joints, bearing several minute, 

 deciduous leaves on their surface ; in the axil of each leaf 

 is a small circular cushion (areole), probably representing 

 an aborted branch, covered with a short wool consisting of 

 many jointed hairs, among which are several barbed bristles, 

 and usually one or more spines. 



Areoles with 1-2 long spines 0. monacantha 1 



Areolcs usually spineless 0. vulgaris 2 



1. Opuntia. monacantha, Haw. Prickly Pear. 

 Erect perennial, 2-5 m. (6-15 ft.) high, branching 

 from base; joints flat, oboval or oblong, rather 

 thick, coalescing with age into stout, woody 

 stems, terminal flower - bearing joints smaller and 

 much thinner, sometimes drooping under the heavy 



