| Calycanthus family | Calycanthaceae | Aromatic shrub; leaves opposite, simple, entire; flowers bisexual, regular, solitary, maroon; fruit of nutlets inside dry, baglike hypanthial tube. |
| Canna family | Cannaceae | Stem, rhizomatous, absence of ligule, Flowers asymmetrical, Zygomorphic, petaloid staminodium, half fertile stamen and warty ovary. |
| Carpetweed family | Molluginaceae | Annual herb, the stems usually prostrate and mat-forming; leaves whorled, simple and linear-lanceolate; flowers bisexual, regular, on pedicels from leaf axils; fruit a capsule. |
| Carrot family | Apiaceae | Annual, biennial, or perennial herbs, often aromatic and with hollow stems; leaves alternate or basal, simple to highly dissected, the petiole bases often sheathing; flowers bisexual or unisexual, mostly regular in simple to compound umbels; fruit a schizocarp. |
| Cat-Tail family | Typhaceae | Perennial herbs, in or near water, strongly rhizomatous, with stems emergent or floating; leaves alternate and distichous, linear and parallel-veined; flowers unisexual (plants monoecious), regular, in dense headlike or cylindric clusters; fruit a drupe or follicle. |
| Catalpa family | Bignoniaceae | Deciduous vines or trees; leaves opposite or whorled, simple or compound; flowers bisexual, irregular; fruit a capsule with winged seeds. |
| Catbrier family | Smilacaceae | Perennial vines with tendrils or erect herbs, the woody vines with prickles; leaves alternate or whorled, simple, with 3-7 pairs of palmate veins converging at apex; flowers unisexual (plants dioecious), regular, in umbels; fruit a blackish or bluish berry (in our species). |
| Citrus family | Rutaceae | Shrubs or small trees, often with citruslike oder; leaves alternate, compound, the leaflets with glandular dots; flowers unisexual or bisexual, regular, in axillary clusters or terminal cymes; fruit types vary. |
| Clethra family | Clethraceae | Small deciduous trees, the bark red-shreddy; leaves alternate, simple, serrate; flowers bisexual, regular, in racemes; fruit a capsule. |
| Club-Moss family | Lycopodiaceae | Stems leafy and mosslike; sporangia-bearing. |
| Colchicum family | Colchicaceae | Perennial herbs that grow from a corm or a rhizome. The leaves may grow directly from the ground, or alternately along a stem. The leaves have parallel veins running lengthwise along the blade and untoothed (entire) margins. |
| Cypress family | Cupressaceae | Shrubs or trees; cone-bearing. |
| Dodder family | Cuscutaceae | Parasitic annual herbs (holoparasites), lacking chlorophyll, with orange-yellow stems threadlike and twining on other plants and attached by haustoria penetrating the tissues of the hosts; leaves alternate and scalelike; flowers bisexual and whitish, regular, in dense clusters; fruit a capsule. |
| Dogbane family | Apocynaceae | Perennial herbs or woody vines, usually with milky sap; leaves simple, entire; flowers bisexual, regular, solitary or in cymes; fruit a pair of follicles; family includes many poisonous species. |
| Dogwood family | Cornaceae | Shrubs and small trees; leaves opposite or alternate, simple, the lateral veins arching toward leaf apex; opposite leaf scars connecting, giving the twig a jointed appearance; flowers regular, in heads or cymes; fruit a drupe. |
| Duckweed family | Lemnaceae | Tiny, annual aquatics, floating on the water surface or suspended beneath, reproducing primarily asexually by budding and fragmentation; plant body a thallus (not distinguishable into stem and leaf); flowers unisexual (but rarely present), consisting of a single stamen or a single pistil; fruit a utricle. |
| Ebony family | Ebenaceae | Deciduous tree with blocky bark; leaves alternate, simple, ovate and entire; flowers unisexual, regular, solitary or in cymes; fruit a berry. |
| Elm family | Ulmaceae | Trees or shrubs; leaves alternate, simple, the base oblique, stipulate; flowers small and greenish, bisexual or unisexual and plants monoecious, regular or irregular; fruit a samara, drupe, or nutlike. |
| Evening-Primrose family | Onagraceae | Annual, biennial, or perennial herbs; leaves various; flowers bisexual, mostly regular; fruit a capsule or nutlike. |
| Figwort family | Scrophulariaceae | Annual or perennial herbs; leaves various; flowers bisexual, regular or irregular, bilabiate in some, in various clusters; fruit a capsule. |
| Flax family | Linaceae | Annual or perennial herbs; leaves alternate (or opposite below); flowers bisexual, regular, in cymose to paniculate terminal clusters; fruit a capsule splitting into 5 or 10 segments. |
| Frog's Bit family | Hydrocharitaceae | Aquatic, perennial herbs; leaves various, simple; flowers mostly unisexual (plants dioecious or monoecious), regular, axillary; fruit an achene in Najas, and berrylike in other genera. |
| Fumitory family | Fumariaceae | Annual, biennial, or perennial herbs; leaves alternate, highly dissected; flowers bisexual, highly irregular with at least one petal spurred or saccate at base, in racemes or panicles; fruit a capsule; all species should be considered poisonous. |
| Gentian family | Gentianaceae | Annual, biennial, or perennial herbs; leaves mostly opposite or whorled, simple, entire; flowers, bisexual, regular, in various clusters; fruit a capsule. |
| Geranium family | Geraniaceae | Annual or perennial herbs; leaves opposite or alternate, lobed to compound, stipulate; flowers bisexual, mostly regular, in various clusters; fruit a beaked capsule, separating at base into 5 mericarps. |
| Ginkgo family | Ginkgoaceae | Family of gymnosperms appearing during the Mesozoic Era, Ginkgo biloba being its only surviving member. |
| Ginseng family | Araliaceae | Herbs or deciduous woody vines or shrubs; leaves various, stipulate; flowers unisexual or bisexual, regular, epigynous, in umbels; fruit a berry. |
| Gooseberry family | Grossulariaceae | Deciduous shrubs; pith chambered or spongy; leaves alternate, simple, stipulate in Itea; flowers bisexual, regular, mostly in racemes; fruit a capsule or berry. |
| Goosefoot family | Chenopodiaceae | Annual to perennial herbs; leaves usually alternate, simple, sometimes succulent; flowers very small, bisexual or unisexual, regular, often congested in leaf axils or in spikes or panicles; fruit an achene, nutlet, or utricle. |
| Gourd family | Cucurbitaceae | Annual or perennial herbaceous vines, usually climbing by coiling tendrils; leaves alternate, simple, often palmately lobed; flowers unisexual (plants usually monoecious), regular; fruit a specialized berry, a pepo, with parietal placentation. |
| Grape family | Vitaceae | Woody vines climbing by tendrils; leaves alternate, simple, and palmately veined, or compound, stipulate; flowers usually bisexual, regular, in various clusters; fruit a berry. |
| Grass family | Poaceae | Annual or perennial herbs, or woody in a few genera; stems terete, internodes hollow or solid; leaves alternate, 2-ranked, simple, and parallel-veined, with sheathing bases, the sheaths usually open, typically with a ligule at junction of sheath and blade; flowers (florets) bisexual or unisexual, subtended by bracts (a lemma and usually a palea), in spikelets usually subtended by a pair of bracts (glumes); fruit a caryopsis. |
| Heath family | Ericaceae | Small shrubs to trees, deciduous or evergreen, often in acidic soils; leaves simple, usually alternate; flowers bisexual, regular, solitary or in racemes; fruit a capsule or berry. |
| Hemp family | Cannabaceae | Members of the family are erect or climbing plants, including trees, lianas (woody vines), and herbaceous plants. The leaves are borne oppositely or in spirals and are often palmately lobed or compound |
| Holly family | Aquifoliaceae | Shrubs or trees, deciduous or evergreen; flowers mostly unisexual (plants usually dioecious), regular, in axillary clusters; fruit a drupe, attracting songbirds, especially robins, catbirds, bluejays, bluebirds, thrushes, and mockingbirds. |
| Honeysuckle family | Caprifoliaceae | Vines, shrubs, or small trees; leaves opposite, simple or compound, stipulate in Viburnum; flowers bisexual, regular or irregular, in cymes; fruit a berry or drupe. |
| Hornwort family | Ceratophyllaceae | Aquatic perennial herbs, rootless and suspended below the water surface; leaves whorled, sessile, divided; flowers unisexual, solitary in leaf axils, plants monoecious; fruit an achene with an apical spinelike beak; family now thought to represent an ancient angiosperm lineage possibly related to some of the earliest flowering plants. |
| Horsetail family | Equisetaceae | Aerial stems erect, hollow, with vertical grooves embedded with silica; leaves scalelike and whorled; sporangia-bearing. |
| Hydrangea family | Hydrangeaceae | Vines or shrubs; leaves opposite, simple; flowers bisexual, regular, in cymes; fruit a capsule. |