37^ i^J5- begoniaceak — i06. axcistrocladaceae — iby. cactaci:ae 



Genus i, species no. Tropical and South Africa. Some species are used as 

 ornamental or medicinal plants or as vegetables. (Including Mezierca 

 Gaud.) Begonia L, 



SUBORDER ANCISTROCLADINEAE 

 FAMILY 166. ANCISTROCLADACEAE 



Climbing, tendril-bearing shrubs. Leaves alternate, undivided, with small, 

 deciduous stipules. Flowers in racemes or panicles, regular, hermaphrodite. 

 Sepals unequal, imbricate in bud. Petals 5, united at the base, with con- 

 torted aestivation. Stamens 10, rarely 9. Filaments united at the base, 

 short. Anthers basifixed, opening inwards by longitudinal shts. Ovary 

 inferior, i-celled. Ovule i, basal, half-inverted. Style simple with 3 stigmas 

 or 3-cleft. Fruit a nut surmounted by the enlarged, wäng-like sepals. Seeds 

 with a thin testa, a repeatedly folded albumen, and a straight embryo. (Under 

 DIP TEROCA RPA CEA E.) 



Genus i, species 2. West Africa Ancistrocladus Wall. 



ORDER OPUNTIALES 



FAMILY 167. CACTACEAE 



Succulent plants with a thickened, usually jointed and spiny stem. Leaves 

 mostly scale-Hke, often deciduous. Flowers sohtary or in clusters, hermaphrod- 

 ite. Perianth of 8 or more segments not distinctly differentiated into sepals 

 and petals. Stamens numerous. Anthers opening inwards or laterally. 

 Ovary inferior, i-celled, with several parietal placentas. Ovules inverted. 

 Style simple, with several stigmas. Fruit a berry. Seeds albuminous ; 

 embryo curved. — Genera 5, species 13. 



1. Leaves well-developed. Stem not jointed. Spines not barbed. Perianth 



wheel-shaped. Ovules f^w, not enveloped by the short funicle. Cotyle- 

 dons intertwisted. — Species i. Naturalized in the Mascarene Islands. 

 A decorative and medicinal plant. [Subfamily PEIRESKIOIDEAE, 



tribe PEIRESKIEAE.] Peireskia Plum. 



Leaves scale-like or absent. Stem more or less copiously jointed. Cotyle- 

 dons not intertwisted 2 



2. Plants destitute of barbed spines. Joints of the stem elongated. Ovules 



not enveloped by the funicle. [Subfamily CEREOIDEAE.] ... 3 

 Plants bearing barbed spines, at least upon the fruit. Joints of the stem 

 short, more or less ovoid. Perianth regular, more or less wheel-shaped. 

 Ovules enveloped by the funicle. [Subfamily OPUNTIOIDEAE, tribe 

 OPUNTIEAE.] / 4 



3. Perianth funnel- or salver-shaped, with obviously united segments. Ovules 



numerous, on long funicles. Terrestrial plants. — Species i. Culti- 

 vated and sometimes naturalized in various regions. A decorative 

 plant with edible fruits. [Tribe ECHINOCACTEAE.] 



Cereus Haw. 



