Lauraceae. Distinguished by polygamous flowers, calyx inferior, petaloid, anthers opened by 2-4 uplifted valves, ovary 1-celled, fruit drupe or berry; composed of 40 genera, 900 species. Sassafras, Cin-namomum.
Rosaceae. Distinguished by prickles, warts on woody surface, flowers regular, stamens inserted on calyx tube, perigynous; composed of 65 genera, 1200 species. Rosa.
Drupaceae. Distinguished by bark exuding gum, bark and seeds containing hydrocyanic acid, calyx 5-lobed, free from ovary, petals (5), stamens (many) inserted on calyx, ovary 1-celled, 2-ovuled, drupe; composed of 6 genera, 110 species. Prunus (Amyqdalus).
Mimosaceae. Distinguished by ovary several-ovuled, fruit legumes, leaves 2-3-pinnate, flowers small, regular, calyx 3-6-lobed, corolla 3-6, stamens distinct or monadelphous, ovary 1-celled; composed of 30 genera, 1350 species. Acacia.
Caisalpinaceae. Distinguished by legumes, upper petal enclosed by lateral ones in the bud, leaves compound, stipulate, flowers perfect, monoecious, dioecious, polygamous, 5's; composed of 90 genera, 1000 species. Cassia (Cathartocarpus), Copaiba.
Papilionaceae. -Distinguished by legumes or loments, upper petal enclosing lateral ones in the bud, leaves compound, stipulate, calyx 4-5-toothed, petals somewhat united (banner, wings, keel), stamens usually 10, pistil 1, superior; composed of 310 genera, 5000 species. Toluifera, Astragalus, Pterocarpus, Glycyrrhiza, Cytisus, Vouacapoua, Physostigma.
Erythroxylaceae. Distinguished from Linaceae by the shrubby or arboreous habit, and by the drupaceous fruit, calyx 5-lobed, petals 5, stamens 10, hypogynous, ovary superior; composed of 3 genera, 60 species. Erythroxylon.