The World Flora Online

Herbs, rarely subshrubs, or small shrubs, rarely dioecious. Stems erect, prostrate, or ascending, usually with conspicuously swollen nodes, glabrous or pubescent, rarely prickly. Leaves simple, alternate, subsessile; leaf blade variously shaped, margin entire; ocrea tubular, membranous, margin entire or lacerate, apex truncate or oblique. Inflorescence terminal or axillary, racemose, spicate, capitate, or paniculate, sometimes flowers fascicled or solitary in axils of leaves. Pedicel often articulate. Flowers bisexual, rarely unisexual; bracts and bracteoles membranous. Perianth persistent, 5(or 4)-parted. Stamens 7 or 8, rarely 4. Styles 2 or 3, deciduous, mostly elongate. Achenes trigonous or biconvex, rarely biconcave.

POLYGONUM L.

Hierbas; plantas hermafroditas. Hojas alternas, enteras; ócreas cilíndricas, en general membranáceas, frecuentemente marginadas o divergentes en el ápice. Inflorescencias en racimos semejantes a espigas, a veces ramificadas, flores amontonadas o laxamente distribuidas, ocréolas infundibuliformes, pedicelos articulados en la base del cáliz; tépalos mayormente 5; estambres 4–8, filamentos erectos o casi erectos; estilos 2 ó 3. Aquenio envuelto en los lobos del perianto, lenticular o 3-angulado o plano-convexo, mayormente negro, lustroso.

El género es frecuentemente dividido, pero en un sentido amplio tiene ca 300 especies con distribución cosmopolita, desde malezas de jardín hasta plantas de ambientes muy húmedos; 6 especies en Nicaragua.

J.K. Small. A monograph of the North American species of the genus Polygonum. Mem. Dept. Bot. Columbia Coll. 1: 1–184. 1895.

This largely temperate genus contains about 150 species, about half of which occur in North America.

Flowers perfect, occasionally with tendencies toward suppression of one sex, with pedicels distally -articulated, usually in ochreolate fascicles. Perianth of 4-5 subequal partially connate tepals, white, green, red or pink. Stamens 5-8 (-9), the filaments discrete, often unequal in length, occasionally adnate to the tepals, the anthers small, versatile, introrse, often isodiametric and appearing peltate. Ovary lenticular or trigonous; styles 2 or 3, terminated by capitate stigmata. Achene usually included, lenticular or trigonous, often beaked, the facies ovate or orbicular. Annual or perennial herbs, sometimes clambering or twining, occasionally shrubby. Leaves alternate, mostly linear to ovate, occasion- ally sagittate, cordate or hastate, the blades mostly exceeding the petioles; ochreae usually conspicuous, often fringed with strigose cilia. Inflorescences of terminal spicate panicles, racemes or cymes, in some species the flowers solitary or fasciculate in the axils; rhachises glabrous to sericeous, occasionally glandular.

Herbes'annuelles ou vivaces et souvent rhizomateuses, terrestres ou aquatiques.'Feuilles'alternes, aiguës ou tronquées à la base, à ochréa membraneuse et généralement ciliée aux bords.'Fleurs'axillaires et solitaires ou par petits groupes ou bien disposées en fascicules cymeux situés à l'aisselle de bractées ochréiformes et groupés en capitules ou en racèmes spiciformes terminaux.'Fleurs'☿, pédicellées et à pédicelle articulé et muni de 2 bractéoles membraneuses et soudées en gaine; périgone à 5 (4) tépales, libres à courtement soudés en cupule à la base, persistants et à peine accrescents; étamines 5-8, insérées sur le réceptacle, incluses ou exsertes, à filets filiformes ou ± dilatés à la base, à anthères oblongues ou dorsifixes; ovaire inclus dans le périgone, comprimé ou trigone, à 2-3 styles, inclus ou exserts et à stigmates capites.'Akènes inclus dans le périgone fructifère, lenticulaires ou trigones, à albumen uni.\n\t\t\t\tGenre renfermant environ 350 espèces répandues dans toutes les régions du globe, mais principalement dans les régions boréales. La plupart des espèces sont très polymorphes et s'hybrident facilement, de telle sorte que leur détermination est fort difficile.

Flowers (in E. African spp.) borne in spiciform racemes or terminal capitula Ocreae with or without a terminal fringe of stiff bristles Hermaphrodite herbs or (rarely) shrubs, glabrous to very hairy, slender or stout, often paludal Styles 2 or 3, often united for part of their length; stigmas capitate Stamens 5–8, included or protruding, a little dilated at the base or conjoined there into a ring Perianth (in E. African spp.) not accrescent, calyciform at the base, with 4–5, often imbricate, petaloid, ± persistent tepals Bracteoles 2, conjoined, thinly membranous and contained within the ocreiform bracts Ripe nuts often black and shining, acutely to obscurely trigonous, or lenticular with convex or concave (dimpled) sides. Ocreae with or without a terminal fringe of stiff bristles Hermaphrodite herbs or (rarely) shrubs, glabrous to very hairy, slender or stout, often paludal Styles 2 or 3, often united for part of their length; stigmas capitate Stamens 5–8, included or protruding, a little dilated at the base or conjoined there into a ring Perianth (in E. African spp.) not accrescent, calyciform at the base, with 4–5, often imbricate, petaloid, ± persistent tepals Bracteoles 2, conjoined, thinly membranous and contained within the ocreiform bracts Ripe nuts often black and shining, acutely to obscurely trigonous, or lenticular with convex or concave (dimpled) sides.

SELECTED REFERENCE

Jones, D. M. and T. R. Mertens. 1970. A taxonomic study of genus Polygonum employing chromatographic methods. Proc. Indiana Acad. Sci. 80: 422-430.

Herbs, shrubs, or subshrubs, annual (perennial in P. striatulum), homophyllous or heterophyllous, sometimes heterocarpic; roots fibrous or woody. Stems prostrate to erect, glabrous, smooth or sometimes papillous-scabridulous. Leaves cauline, alternate (opposite in P. humifusum), petiolate or sessile; ocrea with distal part persistent, often hyaline, white or silvery, 2-lobed, chartaceous, glabrous, disintegrating into fibers, or disintegrating completely; petiole base articulated with ocrea or not; blade linear, lanceolate, elliptic, ovate, or subround, margins entire. Inflorescences axillary or axillary and terminal, spikelike, or flowers solitary; peduncle absent. Pedicels present or absent. Flowers bisexual, 1-7(-10) per ocreate fascicle, base not stipelike; perianth nonaccrescent, white or greenish white to pink, campanulate to urceolate, glabrous; tepals 5, connate 3-70% of their length, petaloid or sepaloid, monomorphic or, rarely, dimorphic, the inner usually flat, the outer flat or sometimes keeled and cucullate distally, sometimes of different length than the inner; stamens 3-8 (some may be reduced to staminodes); filaments distinct, free or adnate to perianth tube, glabrous; anthers whitish yellow, pink to purple or orange-pink, elliptic to oblong; styles (2-)3, mostly spreading, distinct or connate proximally; stigmas 2-3, capitate. Achenes included or exserted, yellow-green, brown, or black, unwinged, (2-)3-gonous, glabrous. Seeds: embryo curved. x = 10.

Annual or perennial prostrate or semi-erect herbs (rarely shrubs), glabrous or hairy. Stamens 4–6, rarely fewer, included or not; filaments broadly dilated in the lower half, free or sometimes united at the base into a ring; anthers globose or ellipsoid, dorsifixed; interstaminal nectaries lacking. Perianth segments (4)5, equal or somewhat unequal in length, spirally arranged, often imbricate, free or united in the lower part, petaloid at least in part, with only one main vein (the vein sometimes branched); outer segments keeled or slightly angular, different from the inner. Nut trigonous, enclosed in the persistent perianth or protruding from it for less than half its length. Ovary included in the perianth; styles (2)3, free; stigmas capitate. Ocrea membranaceous, silvery or white, often deeply lacerate, glabrous. Flowers hermaphrodite, rarely unisexual, solitary or in sessile fascicles springing from the axils of bracts; bracteoles 2, fused, thinly membranous and contained within the bracts. Stems much branched. Leaves alternate, small, usually less than 2 cm long and articulated at the base, lanceolate-elliptic to oblong. Stamens 4–6, rarely fewer, included or not; filaments broadly dilated in the lower half, free or sometimes united at the base into a ring; anthers globose or ellipsoid, dorsifixed; interstaminal nectaries lacking. Perianth segments (4)5, equal or somewhat unequal in length, spirally arranged, often imbricate, free or united in the lower part, petaloid at least in part, with only one main vein (the vein sometimes branched); outer segments keeled or slightly angular, different from the inner. Nut trigonous, enclosed in the persistent perianth or protruding from it for less than half its length. Ovary included in the perianth; styles (2)3, free; stigmas capitate. Ocrea membranaceous, silvery or white, often deeply lacerate, glabrous. Flowers hermaphrodite, rarely unisexual, solitary or in sessile fascicles springing from the axils of bracts; bracteoles 2, fused, thinly membranous and contained within the bracts. Stems much branched. Leaves alternate, small, usually less than 2 cm long and articulated at the base, lanceolate-elliptic to oblong.