The World Flora Online

Herbs, clambering subshrubs, shrubs, or lianas. Leaves alternate or opposite, entire, exstipulate. Flowers small, bisexual or unisexual, or sterile and reduced, subtended by 1 membranous bract and 2 bracteoles, solitary or aggregated in cymes. Inflorescences elongated or condensed spikes (heads), racemes, or thyrsoid structures of varying complexity. Bracteoles membranous or scarious. Tepals 3-5, membranous, scarious or subleathery, 1-, 3-, 5-, or 7(-23)-veined. Stamens as many as tepals and opposite these, rarely fewer than tepals; filaments free, united into a cup at base or ± entirely into a tube, filament lobes present or absent, pseudostaminodes present or absent; anthers (1- or)2-loculed, dorsifixed, introrsely dehiscent. Ovary superior, 1-loculed; ovules 1 to many; style persistent, short and indistinct or long and slender; stigma capitate, penicillate, 2-lobed or forming 2 filiform branches. Fruit a dry utricle or a fleshy capsule, indehiscent, irregularly bursting, or circumscissile. Seeds lenticular, reniform, subglobose, or shortly cylindric, smooth or verruculose.

Seeds globose, compressed or ellipsoid, smooth; embryo annular, surrounding the copious endosperm Ovary superior, 1-celled; style short or long; stigma capitate or 2–3-fid; ovules solitary or rarely several, on basal funicles Fruit dehiscing by a lid or indehiscent Stamens mostly 5, opposite the sepals, hypogynous; filaments united at the base into a short tube, often with staminodes between; anthers 1–or 2-celled, opening by longitudinal slits Annual or perennial herbs, rarely undershrubs or climbers; leaves alternate or opposite, simple, exstipulate Flowers actinomorphic, usually hermaphrodite, small, in spikes, heads or racemes, with often scarious bracts and bracteoles, the latter sometimes hooked Sepals 3–5, free or nearly so, imbricate, more or less dry and membranous Petals absent Ovary superior, 1-celled; style short or long; stigma capitate or 2–3-fid; ovules solitary or rarely several, on basal funicles Fruit dehiscing by a lid or indehiscent Stamens mostly 5, opposite the sepals, hypogynous; filaments united at the base into a short tube, often with staminodes between; anthers 1–or 2-celled, opening by longitudinal slits Annual or perennial herbs, rarely undershrubs or climbers; leaves alternate or opposite, simple, exstipulate Flowers actinomorphic, usually hermaphrodite, small, in spikes, heads or racemes, with often scarious bracts and bracteoles, the latter sometimes hooked Sepals 3–5, free or nearly so, imbricate, more or less dry and membranous Petals absent

Fls small, hypogynous or nearly so, generally regular, perfect or less often unisexual; sep mostly 3–5, seldom only 1 or 2 or even wanting, generally dry and scarious or membranous, distinct or ± connate at the base; pet none; stamens generally as many as the sep and opposite them, seldom fewer; filaments distinct or more often connate at the base into a tube, the tube often produced into teeth or lobes between the anthers, in extreme cases (e.g., Froelichia) the androecium simulating a small, sympetalous cor with filaments attached at the sinuses; gynoecium of 2–3(–4) carpels united to form a compound, unilocular ovary with a single, often evidently lobed style; ovule usually solitary and basal, or in a few genera (e.g., Celosia) the ovules several on a basal or short, free-central placenta; ovules ± distinctly campylotropous; fr a utricle or a small nut, or a circumscissile, 1-seeded capsule (pyxis), often subtended or ± enclosed by the persistent cal; seeds lenticular, with an elongate, dicotyledonous embryo surrounding the abundant perisperm; herbs, seldom climbers or shrubs, producing betalains but not anthocyanins, with simple, exstipulate, alternate or opposite lvs; fls solitary to more often in cymose or variously compound infls, often subtended by scarious or membranous (sometimes conspicuously pigmented) bracts or bracteoles. 65/900.

Herbes'annuelles ou vivaces, sous-arbustes, rarement lianes.'Feuilles'simples, alternes ou opposées, sans stipules.'Inflorescences'souvent très denses en panicules spiciformes ou capitules globuleux, formées de cymules limitées par des bractées souvent scarieuses, vertes ou colorées.'Fleurs'petites, ☿ ou diclines, souvent polygames, actinomorphes, typiquement par 3 entre deux bractéoles; les fleurs latérales souvent ± réduites ou absentes, ou transformées en organes de dissémination; périgone souvent scarieux comme les bractéoles et les bractées, persistant en général autour du fruit, formé de 5-3 segments libres ou ± soudés, souvent entouré de poils; étamines 5-1, opposées aux segments, à filets souvent soudés entre eux ± haut et alternant fréquemment avec des appendices membraneux (staminodes ou « pseudostaminodes »); anthères à 4 ou 2 sacs polliniques; ovaire supère, 3-2-carpellaire, 1-loculaire, à placentation basilaire, pluri- ou, plus souvent, 1-ovulé; ovules campylotropes; style souvent nul; stigmates linéaires, capités ou en pinceau.'Fruits': capsules à déhiscence souvent transversale, ou akènes, rarement baies.'Graines arrondies ou réniformes; embryon en fer à cheval ou circulaire, entourant l'albumen farineux.\n\t\t\tGrande famille bien représentée surtout dans les régions chaudes, comptant 64 genres et près de 1000 espèces, dont, respectivement, 18 et 63 ont été observés au Congo belge.\n\t\t\tCe sont des herbes des sous-bois ( Celosia ,'Pupalia ,'Cyathula ), ou des chaméphytes de savane ( Pandiaka ,'Mechowia ,'Psilotrichum ,'Ackyropsis ), parfois des lianes ( Sericostachys ), mais, très souvent, des plantes anthropophiles, à caractère rudéral ± accusé, extrêmement communes et envahissantes, dont plusieurs (des genres'Alternanthera ,'Amaranthus ,'Celosia ,'Achyranthes ,'Cyathula ,'Aerva ) comptent parmi les « mauvaises herbes » cosmopolites les plus répandues dans les régions chaudes et tempérées chaudes.\n\t\t\tBeaucoup présentent de remarquables organes de dissémination animale, formés soit par les bractéoles ou le périgone, soit par les fleurs latérales stériles, organes pourvus de pointes ou de crochets (glochides :\n\t\t\t\n\t\t\t\t Achyrantes ,'Cyathula ,'Pupalia ); chez'Sericostachys , les fleurs latérales se transforment après l'anthèse en longues barbes plumeuses assurant la dissémination par le vent.\n\t\t\tLes feuilles de plusieurs'Celosia'et'Amaranthus'sont consommées en légume, parfois cultivés pour cela par les noirs, tandis que'A. caudatus'l'est pour sa graine dans les régions montagneuses de l'Est, où des essais de sélection ont été entrepris. Enfin, plusieurs Amaranthacées sont cultivées comme ornementales ( Celosia ,'Gomphrena ,'Amaranthus ,'Alternanthera ).

Seeds round to lenticular or ovoid; embryo curved or circular, surrounding the ± copious endosperm Fruit an irregularly rupturing or circumscissile capsule, rarely a berry or crustaceous, usually with thin membranous walls Ovary superior, 1-locular; ovules 1-many, erect to pendulous, placentation basal; style very short to long and slender; stigmas capitate to long and filiform Stamens as many as and opposite to the petals, rarely fewer; filaments free or commonly fused into a cup at the base, sometimes almost completely fused and 5-toothed at the apex with entire or deeply lobed teeth, some occasionally without anthers, sometimes alternating with variously shaped pseudostaminodes (see note below); anthers 1–2-locular Perianth uniseriate, membranous to firm and finally ± indurate, usually falling with the ripe fruit included, tepals free or somewhat fused below, frequently ± pilose or lanate, green to white or variously coloured Leaves simple, alternate or opposite, exstipulate, entire or almost so Annual or perennial herbs or subshrubs, rarely lianes Flowers hermaphrodite or unisexual (plants dioecious or monoecious), mostly actinomorphic, usually bibracteolate, frequently in ultimate 3-flowered cymules; lateral flowers of such cymules sometimes modified into scales, spines, bristles, hairs or hooks Inflorescence a dense head, loose or spike-like thyrse, spike, raceme or panicle, basically cymose, bracteate; bracts hyaline to white or coloured, subtending 1 or more flowers Fruit an irregularly rupturing or circumscissile capsule, rarely a berry or crustaceous, usually with thin membranous walls Ovary superior, 1-locular; ovules 1-many, erect to pendulous, placentation basal; style very short to long and slender; stigmas capitate to long and filiform Stamens as many as and opposite to the petals, rarely fewer; filaments free or commonly fused into a cup at the base, sometimes almost completely fused and 5-toothed at the apex with entire or deeply lobed teeth, some occasionally without anthers, sometimes alternating with variously shaped pseudostaminodes (see note below); anthers 1–2-locular Perianth uniseriate, membranous to firm and finally ± indurate, usually falling with the ripe fruit included, tepals free or somewhat fused below, frequently ± pilose or lanate, green to white or variously coloured Leaves simple, alternate or opposite, exstipulate, entire or almost so Annual or perennial herbs or subshrubs, rarely lianes Flowers hermaphrodite or unisexual (plants dioecious or monoecious), mostly actinomorphic, usually bibracteolate, frequently in ultimate 3-flowered cymules; lateral flowers of such cymules sometimes modified into scales, spines, bristles, hairs or hooks Inflorescence a dense head, loose or spike-like thyrse, spike, raceme or panicle, basically cymose, bracteate; bracts hyaline to white or coloured, subtending 1 or more flowers

SELECTED REFERENCES

Carolin, R. C. 1983. The trichomes of the Chenopodiaceae and Amaranthaceae. Bot. Jahrb. Syst. 103: 451-466. Eliasson, U. H. 1988. Floral morphology and taxonomic relations among the genera of Amaranthaceae in the New World and the Hawaiian Islands. Bot. J. Linn. Soc. 96: 235-283. Robertson, K. R. 1981. The genera of Amaranthaceae in the southeastern United States. J. Arnold Arbor. 62: 267-314. Standley, P. C. 1915. The North American tribes and genera of Amaranthaceae. J. Wash. Acad. Sci. 5: 391-396. Standley, P. C. 1917b. Amaranthaceae. In: N. L. Britton et al., eds. 1905+. North American Flora.... 47+ vols. New York. Vol. 21, pp. 95-169.

Herbs, rarely subshrubs, annual or perennial; trichomes simple (branched in Tidestromia). Stems without nodal spines (Amaranthus spinosus sometimes with paired nodal spines). Leaves alternate or opposite, exstipulate, usually petiolate; blade margins entire (entire or serrulate in Iresine; entire, crispate, or erose in Amaranthus). Inflorescences cymules arranged in spikes, panicles, thyrses, heads, glomerules, clusters, or racemes; each flower subtended by 1 bract and 2 bracteoles (latter sometimes 1 or absent in Amaranthus). Flowers bisexual or unisexual (plants then monoecious or dioecious), hypogynous, generally small or minute; tepals mostly (1-)4-5 or absent, distinct or connate into cups or tubes, scarious, chartaceous, membranaceous, or indurate; stamens 2-5, filaments basally connate into cups or tubes, rarely distinct, alternating with pseudostaminodes (appendages on staminal tubes) or not, anthers 2-locular with 1 line of dehiscence or 4-locular with 2 lines of dehiscence; ovary superior, 1-locular; ovules 1 or, rarely, 2-many; style 1 or absent; stigmas 1-3(-5). Fruits utricles, dry, dehiscent or not. Seeds black, reddish brown, or brown, lenticular, subglobose or globose (rarely cylindric), usually small; embryo peripheral, surrounding mealy perisperm.

Inflorescence a dense head, loose or dense and spike-like thyrse, spike, raceme or panicle, basically cymose, bracteate; bracts hyaline to membranous, stramineous to white, subtending one or more flowers Leaves simple, alternate or opposite, exstipulate, entire or nearly so Annual or perennial herbs or shrubs, rarely trees or lianes Flowers hermaphrodite or unisexual (plants dioecious or monoecious), mostly actinomorphic, usually bibracteolate, frequently in ultimate 3-flowered cymules; lateral flowers of such cymules sometimes sterile, modified into scales, spines, hooks or hairs Ovary superior, unilocular; ovules commonly solitary, sometimes more numerous, erect to pendulous, placentation basal; style obsolete to long and slender; stigmas capitate to long and filiform Fruit an irregularly rupturing or circumcissile capsule, rarely a berry or crustaceous, usually with rather thin, membranous walls; seeds round to lenticular or ovoid, embryo curved or circular, surrounding the more or less copious endosperm Perianth uniseriate, membranous to firm and finally indurate, usually falling with the ripe fruit included, tepals free or more or less fused below, frequently more or less pilose or lanate, green to white or variously coloured Stamens isomerous with and opposite the tepals, rarely fewer; filaments free or frequently more or less fused below, sometimes almost completely fused and 5-toothed at the apex with entire or deeply lobed teeth, occasionally some anantherous, alternating with variously shaped pseudostaminodes or not; anthers unilocular or bilocular Leaves simple, alternate or opposite, exstipulate, entire or nearly so Annual or perennial herbs or shrubs, rarely trees or lianes Flowers hermaphrodite or unisexual (plants dioecious or monoecious), mostly actinomorphic, usually bibracteolate, frequently in ultimate 3-flowered cymules; lateral flowers of such cymules sometimes sterile, modified into scales, spines, hooks or hairs Ovary superior, unilocular; ovules commonly solitary, sometimes more numerous, erect to pendulous, placentation basal; style obsolete to long and slender; stigmas capitate to long and filiform Fruit an irregularly rupturing or circumcissile capsule, rarely a berry or crustaceous, usually with rather thin, membranous walls; seeds round to lenticular or ovoid, embryo curved or circular, surrounding the more or less copious endosperm Perianth uniseriate, membranous to firm and finally indurate, usually falling with the ripe fruit included, tepals free or more or less fused below, frequently more or less pilose or lanate, green to white or variously coloured Stamens isomerous with and opposite the tepals, rarely fewer; filaments free or frequently more or less fused below, sometimes almost completely fused and 5-toothed at the apex with entire or deeply lobed teeth, occasionally some anantherous, alternating with variously shaped pseudostaminodes or not; anthers unilocular or bilocular