PASSIFLORIN^:. 



477 



Order 6. Datiscacese. 4 species, especially in the Tropics. 

 Datisca cannabini (Asia Minor) resembles the Hemp in external 

 appearance. The flowers are dioecious, insignificant; ^-flowers: 

 a low, gamosepalous calyx, no corolla, and an indefinite number of 

 stamens ; ? -flowers ; epigynous; ovary unilocular with free, mostly 

 bifid, styles, and generally 3 parietal placentae. In most cases the 

 ovary is not entirely closed at the top (as in Reseda). 



Order 7. Begoniacese. This order principally comprises 

 herbs or under-shrubs with succulent stems (having scattered vas- 

 cular bundles in the pith); the leaves are arranged in two rows 



FIG. 516. Begonia rex (reduced). 



(a divergence of |) and are asymmetrical, as a rule more or less 

 obliquely cordate, or ovate with cordate base (Fig. 516) ; large, 

 caducous stipules are present. Inflorescences dichasial, or uni- 

 pared scorpioid cymes ; the flowers are unisexual ; the first ones 

 (the oldest) are ^-flowers, while $ -flowers are found especially 

 on the younger axes. The < -flowers have most frequently 2 + 2 

 coloured perianth-leaves, and many stamens collected into a head 

 in the centre of the flower ; the ? -flowers are epigynous with 5 

 coloured perianth-leaves (placed spirally with a divergence of -f) 

 and a trilocular ovary, bearing 3 bifid styles and 3 wings (the 

 wings usually of unequal size); in the inner angle of each loculus 



