Amaranthaceae Juss.

Amaranthaceae, C. C. Townsend. Flora Zambesiaca 9:1. 1988

Morphology General Habit

Annual or perennial herbs or shrubs, rarely trees or lianes

Morphology Leaves

Leaves simple, alternate or opposite, exstipulate, entire or nearly so

Morphology Reproductive morphology Inflorescences

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

Morphology Reproductive morphology Flowers

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

Morphology Reproductive morphology Flowers Perianth

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

Morphology Reproductive morphology Flowers Androecium

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

Morphology Reproductive morphology Flowers Gynoecium

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

Morphology Reproductive morphology Fruits

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

Amaranthaceae, Hutchinson and Dalziel. Flora of West Tropical Africa 1:1. 1954

Morphology General Habit

Annual or perennial herbs, rarely undershrubs or climbers; leaves alternate or opposite, simple, exstipulate

Morphology Reproductive morphology Flowers

Flowers actinomorphic, usually hermaphrodite, small, in spikes, heads or racemes, with often scarious bracts and bracteoles, the latter sometimes hooked

Morphology Reproductive morphology Flowers Calyx

Sepals 3–5, free or nearly so, imbricate, more or less dry and membranous

Morphology Reproductive morphology Flowers Corolla

Petals absent

Morphology Reproductive morphology Flowers Androecium

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

Morphology Reproductive morphology Flowers Gynoecium

Ovary superior, 1-celled; style short or long; stigma capitate or 2–3-fid; ovules solitary or rarely several, on basal funicles

Morphology Reproductive morphology Fruits

Fruit dehiscing by a lid or indehiscent

Morphology Reproductive morphology Seeds

Seeds globose, compressed or ellipsoid, smooth; embryo annular, surrounding the copious endosperm

Amaranthaceae, C.C. Townsend. Flora of Tropical East Africa. 1985

Morphology General Habit

Annual or perennial herbs or subshrubs, rarely lianes

Morphology Leaves

Leaves simple, alternate or opposite, exstipulate, entire or almost so

Morphology Reproductive morphology Inflorescences

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

Morphology Reproductive morphology Flowers

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

Morphology Reproductive morphology Flowers Perianth

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

Morphology Reproductive morphology Flowers Androecium

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

Morphology Reproductive morphology Flowers Gynoecium

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

Morphology Reproductive morphology Fruits

Fruit an irregularly rupturing or circumscissile capsule, rarely a berry or crustaceous, usually with thin membranous walls

Morphology Reproductive morphology Seeds

Seeds round to lenticular or ovoid; embryo curved or circular, surrounding the ± copious endosperm

Zappi, D. (2009). Neotropical Chenopodiaceae.

Morphology

Description

Annual , rarely perennial herbs, subshrubs or shrubs, rarely lianas; plants dioecious , polygamous or monoecious .  Leaves simple , alternate , estipulate, entire to lobed , rarely deeply lobed . Inflorescence racemose or paniculate, cymose, bracteate; bracts transparent , membranous , white, green, red or wine coloured, subtending one or more flowers. Flowers small, hermaphrodite or rarely unisexual, usually actinomorphic , bracteolate; sepals (= tepals) usually 3-5, rarely fewer, free , scale-like or membranous ; petals absent; stamens usually 3-5, opposite tepals, free , anthers 1-2-locular; ovary superior , 2(-3)-carpelate, 1-locular, placentation basal , 1 style , stigma< /A> of variable form.  dehiscent capsules; seeds black, testa shiny.

General Description

Notes on delimitation

• The Chenopodiaceae is treated as part of a larger, all-encompassing family the Amaranthaceae by some authors (Giannasi et al. 1992, Cuénoud et al. 2002, APG II, 2003, Souza & Lorenzi 2005). 
• Recent molecular studies using the markers rbcL and matK resolve Amaranthaceae-Chenopodiaceae as sister to the Achatocarpaceae (Kadereit et al. 2003, Cuénoud et al. 2002) and this evidence is supported by existing morphological data.

Number of genera

1. Beta L. - Beta vulgaris L. is the well known edible beetroot.2. Chenopodium L.- a genus with a few medicinal representatives, the better known one being C. ambrosioides L., popularly known as mastruz and erva-de-Santa-Maria in Brazil: a toxic invasive plant that is reported as a treatment for many diseases.3. Spinacia L. - Spinacia oleracea L., the popular spinach, is a good source of iron.4. Salicornia L. - species of this genus are adapted to grow in salty marshes and lagoons.

Status

• Mostly introduced, cultivated or naturalized, with some native, weedy species (Salicornia).

Distribution

Distribution in the Neotropics

• In the Neotropics, the Chenopodiaceae is represented largely by invasive species and some introduced, cultivated plants. The list of genera below includes the genera reported from Mexico, Central and South America, and the Caribbean.

Diagnostic

Distinguishing characters (always present)

• Plants with alternate, simple, estipulate leaves with entire margins.
• Flowers small, several clustered in inflorescences.
• A bract and two bracteoles support a flower.
• Sepals (= tepals) present, free< /A> ; petals absent.

Key differences from similar families

• Distinct from Amaranthaceae due to its alternate leaves, often lobed or variously divided. Differs from Achatocarpaceae because of its herbaceous (vs. woody) habit and dry (vs. succulent) fruits.

Useful tips for generic identification

Key to genera of Neotropical Chenopodiaceae

1. Plants with swollen root — Beta
1. Plants without swollen root — 2

2. Leaves reduced, stems swollen — Salicornia
2. Leaves present, well developed ... 3

3. Leaves with crenate or deeply lobed margins ... Chenopodium
3. Leaves deltoid, with straight margins ... Spinacia

Literature

Important literature

APG II, 2003. An update of the Angiosperm Phylogeny group classification for the orders and families of flowering plants: APG II. Bot. J. Linn. Soc. 141(4): 399-436.

Cuénoud, P., V. Savolainen, L.W. Chatrou, M. Powell, R.J. Grayer & M.W. Chase. 2002. Molecular phylogenetics of Caryophyllales based on nuclear 18S RDNA and plastid rbcL, atpB, and matK  DNA sequences. Amer.J.of Bot. 89(1): 132-144.

Giannasi, D.E., G. Zurawski, G.H. Learn & M.T. Clegg. 1992. Evolutionary relationships of the Caryophyllidae based on comparative rbcL sequences. Syst.Bot.17:1-15.

G. Kadereit, T. Borsch, K. Weising and H. Freitag.  2003. Phylogeny of Amaranthaceae and Chenopodiaceae and the Evolution of C3 Photosynthesis. Int. J. Pl.Sci. 164: 959-986.

Müller K. & T. Borsch. 2005. Phylogenetics of Amaranthaceae based on matK/trnK sequence data - Evidence from Parsimony, Likelihood, and Bayesian analyses. Ann. Missouri Bot. Gard. 92:66-102.

Souza, V.C. & Lorenzi, H. 2005. Botânica Sistemática: guia ilustrativo para identificação das famílias de Angiospermas da flora brasileira, baseado em APG II. Nova Odessa, Brazil: Instituto Plantarum.

Chenopodiaceae, J. P. M. Brenan. Flora of Tropical East Africa. 1954

Morphology General Habit

Mostly annual or perennial herbs, sometimes shrubs, rarely small trees, often halophytic and with tendency to fleshiness

Morphology Leaves

Leaves alternate, rarely opposite, simple, without stipules, entire or not, but characteristically never regularly serrate; sometimes the leaves reduced to scales

Morphology Reproductive morphology Flowers

Flowers small to minute, mostly green to grey, solitary and axillary, or more often variously clustered, usually regular, A5; or ? and ?

Morphology Reproductive morphology Flowers Calyx

Calyx (1–) 2–5-lobed, lobes more or less united below, imbricate or almost valvate, persistent after flowering, or variously modified in fruit

Morphology Reproductive morphology Flowers Corolla

Petals absent

Morphology Reproductive morphology Flowers Androecium

Stamens as many as or fewer than sepals, and opposite them

Morphology Reproductive morphology Flowers Gynoecium

Ovary normally free and superior, 1-celled Ovule solitary, campylotropous, on a long or short almost always basal funicle Stigmas 2 (–5)

Morphology Reproductive morphology Fruits

Fruit usually utricular, indehiscent, rarely circumscissile, often included in and falling with the calyx

Morphology Reproductive morphology Seeds

Embryo peripheral, curved, annular or spiral, surrounding the endosperm, which may be absent The presence or absence of endosperm and the position and shape of the embryo are characters very valuable for separating certain genera in this family. They are not employed in the following key, but are given in the generic descriptions

Chenopodiaceae, J.P.M.. Brenan. Flora of West Tropical Africa 1:1. 1954

Morphology General Habit

Mostly annual or perennial herbs, sometimes shrubs, rarely small trees, often halophytic and with tendency to fleshiness

Morphology Leaves

Leaves alternate, rarely opposite, simple, without stipules, entire or not, but characteristically never regularly serrate; sometimes the leaves reduced to scales

Morphology Reproductive morphology Flowers

Flowers small to minute, mostly green to grey, solitary and axillary, or more often variously clustered, usually regular, hermaphrodite or unisexual

Morphology Reproductive morphology Flowers Calyx

Calyx (1–) 2–5-lobed, lobes more or less united below, imbricate or almost valvate, persistent after flowering, or variously modified in fruit

Morphology Reproductive morphology Flowers Corolla

Petals absent

Morphology Reproductive morphology Flowers Androecium

Stamens as many as or fewer than sepals, and opposite them

Morphology Reproductive morphology Flowers Gynoecium

Stigmas 2 (–5) Ovule solitary, campylotropous, on a long or short almost always basal funicle Ovary normally free and superior, one-celled

Morphology Reproductive morphology Fruits

Fruit usually utricular, indehiscent, rarely circumscissile, often included in and falling with the calyx

Morphology Reproductive morphology Seeds

Embryo peripheral, curved, annular or spiral, surrounding the endosperm, which may be absent

Chenopodiaceae, J. P. M. Brenan. Flora Zambesiaca 9:1. 1988

Morphology General Habit

Mostly annual or perennial herbs, sometimes shrubs rarely small trees, often halophytic or nitrophilous and with tendency to fleshiness

Morphology Leaves

Leaves alternate, rarely opposite, simple, without stipules, entire or not; sometimes leaves reduced to scales or green ring-like joints along the stem

Morphology Reproductive morphology Flowers

Flowers small to minute, mostly green or grey, solitary and axillary, or more often variously clustered or cymose, usually regular, unisexual or male and female

Morphology Reproductive morphology Flowers Perianth

Perianth (1) 2–5 (or more, but not in the Flora Zambesiaca area) lobed; lobes united below, imbricate or almost valvate, presistent, after flowering, or variously modified in fruit

Morphology Reproductive morphology Flowers Corolla

Petals and sepals not differentiated

Morphology Reproductive morphology Flowers Androecium

Stamens as many as or fewer than the perianth segments, and opposite them

Morphology Reproductive morphology Flowers Gynoecium

Ovule solitary, campylotropous on a long or short almost always basal funicle Ovary normally free and superior, unicellular Stigmas 2 (5)

Morphology Reproductive morphology Fruits

Fruit usually utricular, indehiscent, rarely circumscissile, often included in and falling with the perianth

Morphology Reproductive morphology Seeds

Embryo peripheral, curved, annular or spiral surrounding the endosperm, or endosperm absent