Anthers opening by 2 slits. Seeds exalbuminous. Leaves undivided, rarely digitate, but then ovary stalked and 2-celled. 436 436. Ovary stalked, 2-celled. Embryo curved. Leaves alternate. =87. Capparidaceae.= Ovary sessile. Embryo straight. Leaves undivided, usually opposite. 437 437. Ovary 2-6-celled. =173. Lythraceae.= Ovary 10-20-celled. Ovules inserted upon the dissepiments. Petals linear. Trees or shrubs. Leaves opposite, exstipulate. _Sonneratia_, =174. Sonneratiaceae=. 438. Calyx and corolla with contorted aestivation. Petals 5-6. Disc present. Ovary 3-celled. Style present. Trees or shrubs. Leaves alternate, not peltate. =140. Chlaenaceae.= Calyx and corolla with imbricate, not contorted aestivation. Petals numerous. Disc wanting. Ovary 6-or more-celled. Style wanting. Herbs. Leaves all radical, floating, peltate. _Nymphaea_, =76. Nymphaeaceae=. 439. (389.) Stamens as many or twice as many as the petals, 3-10. 440 Stamens numerous. 446 440. Petals and stamens perigynous or inserted at the base of an hypogynous disc. Stamens 8 or 10. Styles free. Seeds albuminous. 441 Petals and stamens hypogynous. Disc wanting. 442 441. Stem herbaceous. Leaves usually radical or alternate and exstipulate. Placentas thick. _Saxifraga_, =96. Saxifragaceae=. Stem woody. Leaves opposite or whorled, stipulate. Ovules in two rows. =98. Cunoniaceae.= 442. Leaves opposite or whorled, undivided, stipulate. Filaments free. Styles free. Seeds exalbuminous. Herbs or undershrubs. =151. Elatinaceae.= Leaves alternate or all radical. 443 443. Sepals united below, valvate in bud. Leaves stipulate. =144. Sterculiaceae.= Sepals free or nearly so, imbricate in bud. 444 444. Ovary-cells and styles 5. Petals with contorted aestivation. Seeds albuminous. =108. Oxalidaceae.= Ovary-cells and styles or style-branches 3. Stamens 10. Trees or shrubs. Leaves undivided. 445 445. Filaments free. Anthers opening at the apex. Style shortly 3-cleft. Ovules in several rows. Albumen abundant. Bracteoles absent. _Clethra_, =188. Clethraceae=. Filaments united at the base. Ovules in two rows. Albumen scanty or wanting. Bracteoles present. _Asteropeia_, =148. Theaceae=. 446. (439.) Petals and stamens perigynous, adnate to the ovary at the base, numerous. Filaments free. Sepals imbricate in bud. Leaves all radical, stipulate. _Nymphaea_, =76. Nymphaeaceae=. Petals and stamens hypogynous, free from the ovary. Petals 3-9. 447 447. Leaves opposite, undivided, exstipulate. Seeds exalbuminous. =149. Guttiferae.= Leaves alternate. 448 448. Petals 8. Sepals 5, imbricate in bud. Filaments free. Styles free. Seeds with a straight embryo and copious albumen. Herbs. Leaves dissected, exstipulate. _Nigella_, =78. Ranunculaceae=. Petals 3-5. Filaments united, at least at the base. 449 449. Sepals 5, free or nearly so, imbricate in bud. Albumen scanty or wanting. Trees or shrubs. Leaves undivided, exstipulate. =148. Theaceae.=