[Vol. 2 



154 ANNALS OF THE MISSOURI BOTANICAL OAKDEN 



Order Loasales. Flowers usually actinomorphic, perfect or 

 diclinous ; pistil mostly tricarpellary, 1-celled, its ovary usually 

 inferior ; placentae parietal and with many ovules ; styles free 

 or connate; leaves ample, entire, lobed or dissected. (Species 

 about 1392.) 



Family 230. Loasaceae. Star-flowers. Herbs (rarely 

 climbing) with opposite or alternate leaves; flowers perfect; 

 sepals and petals dissimilar, mostly 5 each ; stamens indefinite, 

 5-10 or more; ovary 3-7-carpellary, 1-celled; endosperm 



mostly 0. Mentzelia, Loasa. (Pf. 3 e M00.) 



Family 231. Cucurbitaceae. Melons. Mostly climbing or 

 prostrate herbs and undershrubs, with alternate leaves; 

 flowers mostly diclinous and pentamerous; stamens definite 

 (usually 3) ; ovary mostly tricarpellary; endosperm 0. Melo- 

 thria, Momordica, Luff a, Citrullus, Cucumis, Lagenaria, 

 Cucurbita. (Pf. 4 r> : 1.) 



Family 232. Begoniaceae. Begonias. Mostly erect herbs 

 with alternate leaves; flowers diclinous, more or less zygo- 

 morphic; stamens indefinite and numerous, ovary tricar- 

 pellary, 3-celled, usually 3-angular; endosperm little or 0. 

 Begonia. (Pf. 3 6a : 121.) 



Family 233. Datiscaceae. Herbs or large trees, with alter- 

 nate leaves ; flowers small, and diclinous ; stamens 4 to many ; 

 ovary 3-8-carpellary ; placentae on the walls; seeds small, and 

 many; endosperm scanty. Datisca. (Pf. 3 6a : 150.) 



Family 234. Ancistrocladaceae. Climbing plants of tropical 

 Asia, with alternate leaves, and small, regular, perfect 

 flowers; petals 5; stamens 5-10; ovary 1-celled, many-se< 

 endosperm present. Ancistrocladus. (Pf. 3 6 : 274.) 



Order Cactales. Flowers actinomorphic or very slightly 

 zygomorphic, perfect; stamens many; pistil 4-8-carpous, in- 

 ferior, 1-celled, with 4-8 parietal placentae ; style single, with 

 2 to many stigmas; endosperm scanty or 0; embryo curved. 

 Fleshy-stemmed plants with leaves mostly small or wanting. 

 (Species about 1168.) 



Family 235. Cactaceae. Cactuses. Mostly natives of the 

 warmer -portions of America; from small herbs to tree-like 



ded 



