The below mentioned article provides an overview on Families of Angiosperms.
Angiosperms = Ovules or seeds enclosed in the ovary.
I. Dicotyledons.
II. Monocotyledons
I. Dicotyledons:
Flowers mostly tetra or pentamerous; leaves net veined; cotyledons usually two; stem commonly with vascular bundles arranged in a ring and open. This class is divided into polypetalae, gamopetalae and monochlamydeae.
A. Polypetalae:
Flowers usually with two distinct whorls of perianth i.e. calyx and corolla; corolla free (polypetalous).
Series 1. Thalainiflorae:
Sepals usually distinct and separate, free from ovary, petals in one, two or many whorls, hypogynous, stamens hypogynous; rarely inserted on a long or short torus or disc; ovary superior.
Order 1. Ranales:
Stamens rarely definite; carpels free or immersed in torus, carpel one or indefinite.
Family. Ranunculaceae:
Plants usually herbs; often with divided leaves; flowers, hermaphrodite, actinomorphic rarely zygomorphic; stamens usually indefinite, gynoecium one or indefinite, superior with one to indefinite ovules; fruit follicle, capsule or rarely berry.
Family. Nymphaeaceae:
Aquatic herbs with large and peltate leaves; flowers hermaprodite, hypogynous to epigynous; tepals many, stamens many carpels many in pits of torus, fruit a spongy berry or an etaerio of achene or nuts.
Order 2. Parietales:
Stamens definite or rarely indefinite; corners united into a unilocular ovary with parietal placentation, rarely superficially two or more locular due to the prolongation of placentae.
Family. Papaveraceae:
Plants usually herbs with alternate leaves and latex; flowers actinomorphic or zygomorpihc; K2, C4 rarely 6 or more; A2-4 or indefinite; G superior, syncarpous, two to sixteen carpel with parietal placentation; indefinite to one ovules; fruit capsule.
Family. Capparidaceae:
Herbs and shrubs with alternate leaves; flowers hermaphrodite, actinomorphic or zygomorphic, axis below androecium or gynoecium is usually elongated; C 4; A indefinite or 6 or 4; gynoecium superior, syncarpous, two to several carpels, unilocular with indefinite ovules, fruit capsule, berry or drupe.
Family. Brassicaceae (Cruciferae):
Herbs with alternate exstipulate leaves, inflorescence racemose; flower actinomorphic, hermaphrodite; K2+2; C4 diagonal; A 2 (short) + 4 (long); G(2) superior, unilocular with superficial partition; fruit siliqua.
Order 3. Caryophyllinae:
Flowers actinomorphic; K2-5 rarely 6; petals usually as many as stamens or twice rarely fewer; Ovary unilocular or imperfectly 2 to 5 locular; free central placentation; embryo usually curved.
Family. Caryophyllaceae:
Herbs or undershrub’s with entire usually opposite leaves; inflorescence cymose or panicle; flowers actinomorphic; K5 or (5) or 0; C5 or O; A 5 or 10; G (5-2) superior, unilocular with free central placentation; ovules one to indefinite; fruit capsule or berry.
Order 4. Malvales:
Flowers regular; K 5 free or united, valvate or imbricate; petals as many or 0; stamens usually indefinite, monadelphous; ovary 3 to multilocular; rarely of one carpel, ovules in inner angles or loculi, axile or basal placentation.
Family. Malvaceae:
Herbs, shrubs or trees with simple or lobed stipulate leaves, flowers hermaphrodite, conspicuous, solitary; K5 often with epicalyx; C5; A indefinite, united below in a tube, monothecous, thorny pollen; G (5- ∞) superior; style as many or twice, fruit capsule or schizocarpic.
Family. Tiliaceae:
Usually woody plants with alternate and stipulate leaves; flowers hermaphrodite, actinomorphic; K5; C5; A indefinite rarely to 10, free or in bundles, anthers dithecous; G (2- ∞) superior, each with 1 to indefinite ovules, two to many locular.
Series 2. Disciflorae:
Sepals distinct or united, free or adnate to ovary; disk usually conspicous as a ring or cushion, or spread over the base of the calyx-tube, or confluent with the base of the ovary, or broken into glands; stamens usually definite, inserted upon or at the outer or inner base of the disk; ovary superior.
Order. Geraniales:
Flower zygomorphic; disk usually annular, adnate to the stamens or reduced to glands rarely 0; ovary of several carpels, syncarpous or sub-apocarpous; ovules 1-2 nearly indefinite, ascending or pendulous, raphe usually ventral.
Family. Rutaceae:
Plants usually woody; leaves alternate or opposite, simple or compound, exstipulate; flowers actinomorphic or zygomorphic, hermaphrodite with disk. A obdiplostamenous or 5-4-3-2 rarely indefinite; G (5-4), superior rarely 3-1 or indefinite with indefinite or 2 ovules.
Family. Meliaceae:
Plants woody, leaves pinnately compound, exstipulate; flowers actinomorphic, hermaphrodite, in cymose panicle; calyx 4-5 lobed, stamens 8-10, monadelphous, gynoecium 2-5, disc annular, syncarpous.
Series 3. Calyciflorae:
Sepals united rarely free, often adnate to ovary; petals uniseriate, peri- or epigynous; disk adnate to the base of calyx rarely raised into torus or gynophore; stamens perigynous; ovary inferior.
Order. Rosales:
Flower hermaphrodite, actinomorphic or zygomorphic; carpels one or more, usually quite free in bud, sometimes variously united afterwards with the calyx-tube or enclosed in swollen top of the peduncle, style usually distinct.
Family. Fabaceae (Leguminosae):
Trees, shrubs or herbs, usually with alternate stipulate leaves and racemes of regular or zygomorphic flowers, hermaphrodite, sepals five polysepalous; corolla polypetalous, petals five, stamens five plus five; gynoecium usually with one carpel, with indefinite ovules; fruit pod.
Family. Rosaceae:
Herbs, shrubs or trees, leaves alternate usually stipulate, flowers regular, pentamerous, axis flat or hollow; sepals five, free; petals five or 0; stamens 2-4 or more, bent inwards in bud; carpels 2-4 or indefinite, free or united to hollow axis, usually unilocular with 2 ovules per carpel; fruit follicle, achene drupe or pome.
Order. Myrtales:
Flowers regular or sub-regular, usually hermaphrodite, ovary syncarpous, usually inferior; style undivided or very rarely free; placentation axile or apical rarely basal; leaves simple usually entire.
Family. Myrtaceae:
Woody plants; leaves opposite or alternate, entire, exstipulate; flowers actinomorphic; sepals and petals usually 4-5; stamens indefinite sometimes in bundles; carpels 2-5 or indefinite, syncarpous, 2-5 or indefinite locular, each loculus with indefinite to one ovule.
Order. Passiflorales:
Flowers usually actinomorphic, hermaphrodite or unisexual; ovary usually inferior, syncarpous, one locular with parietal placentation sometimes 3 or more locular by the extended placentae, style free or connate.
Family. Cucurbitaceae:
Flower pentamerous, usually male or female, unisexual, regular cuplike axis; stamens 5 free, at the edge of axis, or each 2 united, or all 5 in a central synandrium; gynoecium tricarpellary; syncarpous, trilocular, with indefinite ovules and usually forked stigmas; fruit-berry-like pepo.
Order. Umbellales:
Flowers actinomorphic, hermaphrodite; stamens definite, ovary inferior; 1-2 or indefinite locular; ovules solitary, pendulus in each loculus from its apex; style free or united at base; seeds with endosperm.
Family. Apiaceae (umbelliferae):
Hollow stem, alternate much divided leaves, umbel inflorecence, simple or compound, ovary bilocular, bicarpellary, syncarpous, inferior with two styles on swollen style base; schizocarpic fruit.
B. Gamopetalae:
Flowers with two whorls of perianth, the inner gamophyllous i.e. corolla gamopetalous.
Series I. Inferae:
Ovary inferior; stamens usually as many as corolla lobes.
Order. Rubiales:
Stamens epipetalous; ovary 2 to many loculed with one to many ovules in each loculus.
Family. Rubiaceae:
Leaves decussate, entire and interpetiolar stipules; flowers in cymes; corolla tubular to rotate, stamens alternating with corolla lobes, gynoecium two, syncarpous, inferior.
Order. Asterales:
Stamens epipetalous, ovary one loculed and one ovuled.
Family. Asteraceae (Compositae):
Inflorescence capitulum or head, calyx usually pappus; corolla regular or strap shaped; anthers syngenesious; ovary inferior; bicarpellary, syncarpous; stigma bifid; basal placentation.
Series 2. Bicarpellatae:
Ovary superior, stamens as many as or fewer than corolla lobes, carpels two.
Order. Gentianales:
Corolla regular hypogynous, stamens epipetalous; leaves generally opposite.
Family. Apocynaceae:
Leaves with latex, cymose inflorescence; corolla funnel shaped; stamens 5 alternating with corolla lobes; epipetalous.
Family. Asclepiadaceae:
Corolla lobes 5 sometimes with appendages forming a corona, pollen usually in pollinia with translators; gynoecium enclosed in staminal tube, united above by style; fruit 2 follicles.
Order. Polemoniales:
Corolla regular, hypogynous; stamens = corolla lobes, epipetalous, ovary 1-5 locular.
Family. Boraginaceae:
Plants roughly hairy with usually alternate simple leaves and scorpioid cymes of actinomorphic pentamerous flowers; gynoecium (2), superior, each with 2 ovules usually with false septum.
Family. Convolvulaceae:
Herbs with twining habit usually with large actinomorphic flowers, stamens epipetalous, G (2) superior each with 2 basal erect ovules on axile placentation.
Family. Solanaceae:
Inflorescence terminal, solitary or cymosely umbelled; actinomorphic pentamerous flowers, G(2) superior, obliquely placed each with indefinite ovules on axile placentation; fruit berry.
Order. Personales:
Flower usually irregular; corolla hypogynous often bilipped; stamens generally fewer than corolla lobes usually four; didynamous or 2; ovary 1-2 or 4-loculed; ovules indefinite.
Family. Scrophulariaceae:
Stamens usually 4 or 2; G(2) superior, axile placentation, ovules many in each locule.
Family. Acanthaceae:
Leaves opposite, inflorescence spike, receme or cymose umbel, flowers hermaphrodite, zygomorphic, pentamerous; stamens 4 or 2 sometimes with 1-3 staminodes; G(2) superior, median, bract conspicuous.
Order. Lamiales:
Corolla usually bilipped, hypogynous; stamens 4 or 2; ovary 2-4 locular; ovule solitary in loculus, calyx persistent.
Family. Lamiaceae:
Cymose inflorescence or verticellaster; corolla bilabiate; stamens 4, didynamous or 2; with or without 2 staminodes; G (2) superior, each with 2 erect ovules; gynobasic style, ovary quadrilocular by false septum.
Family. Verbanaceae:
Herbs or woody, leaves opposite or whorled, flower hermaphrodite, zygomorphic, K and C gamo- often bilipped, stamens four, G (2) superior rarely more tetralocular.
C. Monochlamydeae:
Flowers usually with one whorl of perianth, commonly sepaloid or none.
Series I. Curvembryae:
Hermaphrodite flowers; stamens generally equal to perianth segments; ovules usually solitary; embryo curved.
Family. Amaranthaceae:
Herbs or shrubs with opposite or alternate exstipulate leaves and small flowers in cymose inflorescence; perianth 4-5 poly or gamophyllous, usually sepaloid, stamens 1-5 and united below; G (2-3) superior, unilocular with 1 to idefinite ovules.
Family. Chenopodiaceae:
Cymose inflorescence, flowers hermaphrodite or male or female; perianth (5), imbricate, sepaloid, stamens as many perianth lobes; G (2) superior, unilocular with single basal ovule.
Series 2. Unisexuales:
Flowers unisexual; ovary syncarpous, or one carpel; ovules solitary or 2 per carpel, perianth sepaloid or much reduced or absent.
Family. Euphorbiaceae:
Leaves alternate or opposite, stipulate; often latex present, compound inflorescence; flowers male or female usually pentamerous; perianth usually in one whorl or zero; stamens one to indefinite, free or united or branched; G (3) superior, trilocular with 2 lobed styles, 1 to 2 pendulous ovules; fruit schizocarpic.
Family. Moraceae:
Trees and shrubs, stipulate leaves and latex; flowers unisexual, small, in catkin or cyme inflorescence, P4 or (4) persistent, A4, antiphyllous; G (2), unilocular being one carpel abortive, one pendulous ovule, style bipartite, fruit sorosis or syconus.
II. Monocotyledons:
Leaves usually with parallel venation, flowers trimerous.
Series I. Epigynae:
Perianth partly petaloid; ovary usually inferior; endosperm abundant.
Family. Musaceae:
Large herbs with ‘false’ stem or trees, compound inflorescence with petaloid bracts; Flowers zygomorphic, hermaphrodite or unisexual, P3 + 3 petaloid; often united, A3+2 and staminode; G (3), ovary inferior, trilocular; fruit berry or capsule.
Family. Amaryllidaceae:
Inflorescence cymose or scape; flowers hermaphrodite, actinomorphic or zygomorphic; perianth 3+3 petaloid; stamens 3+3 usually introrse often with stipular corona; G (3) inferior, rarely half inferior; trilocular with indefinite ovules; fruit capsule or berry.
Series 2. Coronarieae:
Inner perianth petaloid; ovary usually free, superior, endosperm abundant, flowers bisexual.
Family. Liliaceae:
Inflorescence recemose type, flowers hermaphrodite, actinomorphic, trimerous; perianth poly or gamophyllous, 3 + 3, petaloid; stamens 3+3, G(2-) (3-) (5)- locular, superior.
Series 3. Calycinae:
Perianth sepaloid, herbaceous or membranous; ovary free, superior, flowers usually unisexual.
Family. Palmae:
Flowers unisexual, spadix inflorescence, gynoecium tricarpellary, apocarpous or syncarpous; unilocular, one ovuled, ovary superior.
Series 4. Glumaceae:
Flowers solitary; sessile in the axils of bracts and arranged in heads or spikelets with bracts; perianth of scales or none; ovary usually unilocular, one ovuled.
Family. Cyperaceae:
Herbs with usually triangled stem; leaves with close sheath; flowers in spikelets or cymes united to large inflorescence; naked, hermaphrodite or male or female flowers; stamens usually 3 to 1, G(3-2) superior, style 3-2, unilocular with single basal ovule.
Family. Poaceae (Gramineae):
Herbs with jointed stem; leaves alternate with split leafsheath and ligule; panicle or spike-like inflorescence; flowers small, hermaphrodite, naked flowers in spikelets; each beginning with 1 or more glumes, then paleae with axillary flowers, stamens usually 3; G monocarpellary, unilocular, single ovule; fruit caryopsis.
George Bentham (1800-1884) and Joseph Hooker (1917-1911) in their book “General Plantarum” have described 202 families and 97205 flowering plant species.