The genera of Hamamelidaceae and Platanaceae in the southeastern United States

Abstract

Witch-hazel Family)Deciduous for evergreen], ± pubescent trees or shrubs.Leaves simple, usually with deciduous stipules [or stipules fused or rarely absent], petiolate, alternate [or opposite], pinnately (or palmately) veined [sometimes dimorphic]; stomal iaxia laracytic.Hairs usually nonglandular, stellate or tufted, the individual membei unicellular (or hairs simple).Inflorescences bracteate, axillary or terminal, ± capitate or spicate (or ± racemose).Flowers ± regular, subhypogynous to subepigynous, bisexual or unisexual (the plants then monoecious [rarely dioecious]); perianth 4(5)-merous, cyclic, 1-or 2-seriate, often reduced or ± absent.Calyx apparently united, 4-or 5(7)-lobed, usual!n ind ± adnate to the fruit or ± absent | or sepals connate or circumscissile | .Corolla apopetalous or absent Stamens 4 alternipetalous with alternating staminodia, or many and indefinite; [connective often conspicuous;] anthers usually basifixed, with 2 or 4 pollen sacs, becoming 2-locular at an thesis; dehiscence longitudinal by a simple slit, or by 1 or 2 vertical valves; pollen mostly 3-colpate (or polyporate).Gynoecium ± syncarpous, usually 2-carpellate; stigmas terminal or introrsely decurrent; styles free, usually spreading; ovary 2-locular, usually somewhat embedded in the receptacle [to inferior | ; placentation ± axile; ovules 1 (2) in each locule and apical (or many),' anatropo : enl 2-integumented, the micropyle upward.Fruits partly inferior or somewhat inclosed by the calyx, with leathery exocarp and bony endocarp, often appearing to separate apically into 4 persistent valves; dehiscence loculicidal, the fruits 2-seeded (or septicidal "Prepared for a <vi,eii< flora oi 1 he southeastern United Slates, a joint project of the Arnold Arboretui ! the Graj Herbarium, made possible through the support of the National Scienu urn.] lion m I • .t .I « < nlc m-i undei the diiection of Reed C. Rollins and Carroll E. Wood, Jr.This treatment follows the style established in the first paper oi Hie series.Jour Arnold Arb.39: 2<)6 .vlo.LKS8 (and continued through volume 4 n In n i o\ u<\ i m Milm n ui is bounded b\ and includes North Carolina Tennessee, Arkansas, and ouisiana 1 he descriptions apply primarily to the plants of this area with supplementary information in brackets.