BEGONIACEAE 817 



12. Opuntia polyacdntha Haw. Stems prostrate, branching into large masses, the 

 joints suborbicular, 5-10 cm. or rarely 15 cm. long, light-green, tuberculate, bearing leaves 

 3-4 mm. long : bristle-cushions rather numerous, all armed, the bristles reddish brown : 

 spines 8-15 together, the 5-10 outer radiant, very slender, whitish, variegated with red, 

 numerous, stouter, reddish brown with paler tips, 3-5 cm. long, half of them deflexed : 

 flowers yellow or orange, varying to purple : fruit obovoid, 3-5 cm. long, spiny : seeds 5-6 

 mm. broad, irregular in shape. 



In dry soil and on plains and prairies, British Columbia to Nebraska, the Indian Territory, New 

 Mexico and Utah. 



13. Opuntia leptocaulis P. DC. Stems with a hard close-grained wood, and a gray 

 scaly bark, branching, often 12-15 dm. tall, the branches slender, terete, or angled in age ; 

 the outer joints loosely attached to one another, 2-3 cm. long, with terete, subulate leaves : 

 spines mostly solitary, about 8 mm. long, in a close sheath : flowers sulphur-yellow, 14-20 

 mm. broad : fruit scarlet, 10-18 mm. long, not juicy, more often proliferous : seeds 2-5, 

 white, flattened. 



In river valleys, Texas and adjacent Mexico. 



Order 22. BEGONIALES. 



Succulent herbs or shubby plants or vines, often with large rootstocks. 

 Leaves alternate : ' blades commonly inequilateral, toothed or lobed. Flowers 

 monoecious, usually somewhat irregular, in simple or compound cymes. Stami- 

 nate flowers with 2 or more sepals, 5 minute petals and numerous stamens whose 

 anthers open by pores or valves. Pistillate flowers with calyx and corolla, and 

 a gynoecium of 2-5 united carpels. Ovary inferior, 2-several-celled or rarely 

 1-celled, the placentae entire or variously lobed. Stigmas curved, twisted or 

 coiled. Ovules numerous. Fruit capsular, equally or unequally winged. 





FAMILY 1. BEGONIACEAE R. Br. BEGONIA FAMILY. 

 Characters of the order. 



1. BEGONIA L. 



Succulent plants, but sometimes shrubby. Leaves alternate : blades oblique, usually 

 toothed, petioled. Flowers in simple or compound cymes, monoecious, the staminate with 

 2 unequal pairs of petals and many stamens, the pistillate with 5 somewhat unequal petals 

 and an inferior 3-celled ovary. Style very short : stigmas spirally twisted. Ovules numer- 

 ous, on 2-lobed placentae. Capsule membranous, unequally 3-winged, one wing much larger 

 than the rest. Seeds numerous, minute. ELEPHANT'S EAR. 



1. Begonia semperflorens Link & Otto. Stems 3-10 dm. tall, more or less branched, 

 usually red : leaf-blades obliquely ovate or reniform, 4-7 cm. broad, palmately nerved, 

 crenate with minutely apiculate teeth ; petioles shorter than the blades : peduncles axillary, 

 simply dichotomous : bracts ciliate-fimbriate : corolla white : larger petals of the staminate 

 flowers 6-14 mm. long and broad, the smaller petals spatulate : capsules drooping ; two 

 angles with narrow rounded wings, the broad wing of the other angle with a rounded outer 

 margin and a straight upper margin. 



In and about swamps, peninsular Florida. Naturalized from South America. 



Order 23. PROTEALES. 



Perennial herbs, or shrubs or trees, natives of the Southern Hemisphere. 

 Leaves alternate, or rarely opposite or whorled : blades simple or compound. 

 Flowers perfect, or occasionally polygamous or dioecious. Perianth of 4 val- 

 vate partially united sepals. Androecium of 4 stamens, one on each sepal. 

 Gynoecium of a single carpel. Ovary free, 1-celled, often oblique. Style 

 terminal. Stigma disk-like, nipple-shaped or capitate. Ovules 1 or two in a 

 cavity. Fruit indehiscent, or often follicular or capsular. Seed with a straight 

 embryo. 

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