=GROUP 4. One carpel or more than one united carpels; ovules on the walls of the ovary; ovary superior; petals present, free from each other.= a) Leaves opposite: b) Stamens more or less united into 3 or more separate bundles; leaves often gland-dotted or with lines of resin; mostly herbaceous; styles free to the base or very nearly so. =Hypericaceæ= bb) Stamens free or more or less united into not more than 2 separate bundles (diadelphous), sometimes adnate to a gynophore; leaves not or very rarely glandular: c) Connective of the anthers produced above the cells; flowers often somewhat zygomorphic (irregular), the lower petal often gibbous or saccate at the base. =Violaceæ= cc) Connective of the anthers not produced beyond the cells; flowers usually actinomorphic (regular) or papilionaceous: d) Flowers actinomorphic (regular), sessile; leaves small and ericoid, more or less connate at the base; stamens free. =Frankeniaceæ= dd) Flowers zygomorphic (irregular); stamens diadelphous; fruit a legume. =Papilionaceæ= aa) Leaves alternate or all radical: b) Stamens numerous (more than 12): c) Filaments more or less connate into a tube or into separate bundles: d) Filaments connate in 1 or 2 and unequal bundles; leaves compound; flowers mostly arranged in dense spikes or heads. =Mimosaceæ= dd) Filaments connate into more than 2 separate bundles opposite the sepals; calyx valvate; fruits prickly. =Tiliaceæ= cc) Filaments free or at most partially adnate to a gynophore: d) Ovary supported on a gynophore; petals often clawed; seeds without endosperm. =Capparidaceæ= dd) Ovary sessile or very nearly so: e) Anthers horse-shoe shaped; ovary placentas 2; ovules numerous; stipules caducous, leaving a wide scar; leaves large, palminerved at the base; pedicels often with 5 large glands below the sepals. =Bixaceæ= ee) Anthers straight or nearly so, opening by apical pores or short pore-like slits: f) Seeds hairy; ovary entire; leaves digitately nerved or lobed; stems annual from a woody rhizome with yellow interior. =Cochlospermaceæ= ff) Seeds not hairy; ovary often deeply lobed, in fruit the carpels becoming nearly free on the enlarged torus; leaves pinnately nerved; stems not annual.