_Plants with papilionaceous or sometimes regular flowers, 10 (rarely 5 and sometimes many) monadelphous, diadelphous, or rarely distinct stamens, and a single simple free pistil, becoming a legume in fruit. Seeds mostly without albumen. Leaves alternate, with stipules, usually compound._ One of the sepals inferior (i.e. next the bract); one of the petals superior (i.e. next the axis of the inflorescence).--A very large order (nearly free from noxious qualities), of which the principal representatives in northern temperate regions belong to the first of the three suborders it comprises. SUBORDER I. Papilionaceæ. Calyx of 5 sepals, more or less united, often unequally so. Corolla inserted into the base of the calyx, of 5 irregular petals (or very rarely fewer), more or less distinctly _papilionaceous_, i.e. with the upper or odd petal (_vexillum_ or _standard_) larger than the others and enclosing them in the bud, usually turned backward or spreading; the two lateral ones (_wings_) oblique and exterior to the two lower, which last are connivent and commonly more or less coherent by their anterior edges, forming the _carina_ or _keel_, which usually encloses the stamens and pistil. Stamens 10, very rarely 5, inserted with the corolla, monadelphous, diadelphous (mostly with 9 united into a tube which is cleft on the upper side, and the tenth or upper one separate), or occasionally distinct. Ovary 1-celled, sometimes 2-celled by an intrusion of one of the sutures, or transversely 2--many-celled by cross-division into joints; style simple; ovules amphitropous, rarely anatropous. Cotyledons large, thick or thickish; radicle incurved.--Leaves simple or simply compound, the earliest ones in germination usually opposite, the rest alternate; leaflets almost always quite entire. Flowers perfect, solitary and axillary, or in spikes, racemes, or panicles. I. Stamens (10) distinct. [*] Leaves palmately 3-foliolate or simple; calyx 4--5-lobed; herbs. (PODALYRIEÆ.) 1. Baptisia. Pod inflated. 2. Thermopsis. Pod flat, linear. [*][*] Leaves pinnate; calyx-teeth short. (SOPHOREÆ.) 3. Cladrastis. Flowers panicled, white. Pod flat. A tree. 4. Sophora. Flowers racemose, white. Pod terete, moniliform. Herbaceous. II. Stamens monadelphous, or diadelphous (9 and 1, rarely 5 and 5); nearly distinct in n. 14. [*] Anthers of two forms; stamens monadelphous; leaves digitate or simple; leaflets entire. (GENISTEÆ.) 5. Crotalaria. Calyx 5-lobed. Pod inflated. Leaves simple. 6. Genista. Calyx 2-lipped. Pod flat. Seed estrophiolate. Leaves simple. Shrubby. 7. Cytisus. Calyx 2-lipped. Pod flat. Seed strophiolate. Leaves 1--3-foliolate. Shrubby. 8. Lupinus. Calyx deeply 2-lipped. Pod flat. Leaves 7--11-foliolate. [*][*] Anthers uniform (except in n. 13 and 29). [+] Leaves digitately (rarely pinnately) 3-foliolate; leaflets denticulate or serrulate; stamens diadelphous, pods small, 1--few-seeded, often enclosed in the calyx or curved or coiled. (TRIFOLIEÆ.)