The genera of Lythraceae in the southeastern United States

Herbs or shrubs [rarely small trees], with quadrangulate or terete stems.Leaves opposite, seldom alternate or whorled, simple, entire, exstipulate.Flowers regular or irregular, axillary or in terminal racemes or spikes, sometimes dimorphic or trimorphic with regard to style and stamen length, bisexual, [3]4-6-merous, with perianth and stamens perigynous, the flowers rarely cleistogamous ; bracteoles 2, opposite on the pedicel, rarely none.Floral tube campanulate to tubular, persistent, often conspicuously nerved; calyx lobes 4-6, alternating with 3-5 deltoid appendages, or the appendages wanting.Petals 0-6, distinct, crumpled, deciduous [rarely persistent], inserted on the inner surface of the floral tube between the calyx lobes.Stamens as many as or twice as many as the petals [or more numerous], often alternately unequal, inserted on the inner surface of the floral tube below the petals, included to exserted; anthers versatile [rarely basifixed], introrse, 2-locular, longitudinally dehiscent.Gynoecium syncarpous, often surrounded at the base by a hypogynous disc, or in irregular flowers the disc on the upper (adaxial) side only; stigma capitate, rarely bilobed; style filiform; ovary superior, free in the floral tube, 2-4[-6]-locular, the septa complete or reduced; placentation axile [rarely parietal] ; ovules anatropous and epitropous, with 2 integuments.Fruit a membranaceous [or leathery] capsule inclosed by the persistent floral tube, septicidally or loculicidally dehiscent or indehiscent, splitting irregularly.Seeds 3 to many, minute or up to ca. 4 mm.long, pyramidal, ovoid, or discoid, sometimes slightly winged, with Prepared for a generic flora oi the southeastern United States, a joint project of the Gray Herbarium and the Arnold Arboretum made possible through the support of George R. Cooley and the National Science Foundation and under the direction of Reed C. Rollins and Carroll E. Wood, Jr.The scheme follows that outlined at the beginning of the series (Jour.Arnold Arb.39: 296-346.1958).The area