Calyx tubular, 12-ribbed, somewhat inflated below, gibbous or spurred at the base on the upper side, 6-toothed at the apex, and usually with as many little processes in the sinuses. Petals 6, very unequal. Stamens mostly 12, approximate in 2 sets, included, unequal. Ovary with a curved gland at the base next the spur of the calyx, 1--2-celled; style slender; stigma 2-lobed. Capsule oblong, few-seeded, early ruptured through one side.--Flowers solitary or racemose, stalked. (Name from κυφός, _gibbous_, from the shape of the calyx.) 1. C. viscosíssima, Jacq. (CLAMMY CUPHEA.) Annual, very viscid-hairy, branching; leaves ovate-lanceolate; petals ovate, short-clawed, purple; seeds flat, borne on one side of the placenta, which is early forced out of the ruptured capsule.--Dry fields, R. I. to Ga., west to Kan. and La. ORDER 42. ONAGRÀCEÆ. (EVENING-PRIMROSE FAMILY.) _Herbs, with 4-merous (sometimes 2--3- or 5--6-merous) perfect and symmetrical flowers; the tube of the calyx cohering with the 2--4-celled ovary, its lobes valvate in the bud, or obsolete, the petals convolute in the bud, sometimes wanting; and the stamens as many or twice as many as the petals or calyx-lobes_, inserted on the summit of the calyx-tube. Style single, slender; stigma 2--4-lobed or capitate. Pollen grains often connected by cobwebby threads. Seeds anatropous, small, without albumen.--Mostly herbs, with opposite or alternate leaves. Stipules none or glandular. [*] Parts of the flower in fours or more. [+] Fruit a many-seeded pod, usually loculicidal. [++] Calyx-limb divided to the summit of the ovary, persistent. 1. Jussiæa. Petals 4--6. Stamens twice as many. Capsule elongated. 2. Ludwigia. Petals 4 or none. Stamens 4. Capsule short. [++][++] Calyx-tube prolonged beyond the ovary (scarcely so in n. 3) and deciduous from it. Flowers 4-merous. 3. Epilobium. Seeds silky-tufted. Flowers small, not yellow. Lower leaves often opposite. 4. Œnothera. Seeds naked. Flowers mostly yellow. Leaves alternate. [+][+] Fruit dry and indehiscent, 1--4-seeded. Leaves alternate. 5. Gaura. Calyx-tube obconical. Filaments appendaged at base. 6. Stenosiphon. Calyx-tube filiform. Filaments not appendaged. [*][*] Parts of the flower in twos. Leaves opposite. 7. Circæa. Petals 2, obcordate or 2-lobed. Stamens 2. Fruit 1--2-seeded, bristly. 1. JUSSIÆ̀A, L. Calyx-tube elongated, not at all prolonged beyond the ovary; the lobes 4--6, herbaceous and persistent. Petals 4--9. Stamens twice as many as the petals. Capsule 4--6-celled, usually long, opening between the ribs. Seeds very numerous.--Herbs (ours glabrous perennials), with mostly entire and alternate leaves, and axillary yellow flowers, in summer. (Dedicated to _Bernard de Jussieu_, the founder of the Natural System of Botany.)