Index of plants by genus
| Species | Common Name | Family |
| Echinacea pallida | Pale Purple Coneflower | Asteraceae |
| Echinacea purpurea | Purple Coneflower | Asteraceae |
| Echinochloa cruzgalli | Barnyard Grass | Poaceae |
| Echinocystis lobata | Wild Bur Cucumber | Cucurbitaceae |
| Eleocharis ovata | Ovate Spike Rush | Cyperaceae |
| Elodea canadensis | Common Waterweed | Hydrocharitaceae |
| Elodea nuttallii | Slender Waterweed | Hydrocharitaceae |
| Elymus canadensis | Canada Wild Rye | Poaceae |
| Epifagus virginiana | Beech Drops | Orobanchaceae |
| Epigaea repens | Trailing Arbutus | Ericaceae |
| Equisetum arvense | Common Horsetail | Equisetaceae |
| Equisetum fluviatile | Water Horsetail | Equisetaceae |
| Equisetum hyemale | Tall Scouring-rush | Equisetaceae |
| Equisetum laevigatum | Smooth Horsetail | Equisetaceae |
| Equisetum scirpoides | Dwarf Scouring-rush | Equisetaceae |
| Equisetum sylvaticum | Wood Horsetail | Equisetaceae |
| Equisetum variegatum | Variegated Scouring-rush | Equisetaceae |
| Erigeron annuus | Annual Fleabane | Asteraceae |
| Erigeron canadensis | Canadian Horseweed | Asteraceae |
| Erigeron philadelphicus | Marsh Fleabane | Asteraceae |
| Erigeron pulchellus | Robin's Plantain | Asteraceae |
| Erigeron strigosus | Rough Fleabane | Asteraceae |
| Eriocaulon aquaticum | Sevenangle Pipewort | Eriocaulaceae |
| Eriocaulon compressum | Flattened Pipewort | Eriocaulaceae |
| Eriophorum vaginatum | Tussock Cotton Grass | Cyperaceae |
| Eryngium yuccifolium | Rattlesnake Master | Apiaceae |
| Erythronium albidum | White Trout Lily | Liliaceae |
| Erythronium americanum | Yellow Trout Lily | Liliaceae |
| Euonymus atropurpurea | Wahoo | Celastraceae |
| Euonymus obovatus | Running Strawberry Bush | Celastraceae |
| Eupatorium album | White-bracted Thoroughwort | Asteraceae |
| Eupatorium altissimum | Tall Boneset | Asteraceae |
| Eupatorium leucolepis | Justiceweed | Asteraceae |
| Eupatorium perfoliatum | Boneset | Asteraceae |
| Eupatorium pilosum | Ragged Thoroughwort | Asteraceae |
| Eupatorium rotundifolium | Round-leaved Thoroughwort | Asteraceae |
| Eupatorium serotinum | Late Boneset | Asteraceae |
| Eupatorium sessilifolium | Upland Boneset | Asteraceae |
| Euphorbia corollata | Flowering Spurge | Euphorbiaceae |
| Euphorbia polygonifolia | Seaside Spurge | Euphorbiaceae |
| Eurybia compacta | Slender Aster | Asteraceae |
| Eurybia divaricata | White Wood Aster | Asteraceae |
| Eurybia macrophylla | Big-leaved Wood Aster | Asteraceae |
| Eurybia schreberi | Schreber's Wood Aster | Asteraceae |
| Eurybia spectabilis | Showy Aster | Asteraceae |
| Euthamia caroliniana | Slender Grass-leaved Goldenrod | Asteraceae |
| Euthamia graminifolia | Common Grass-leaved Goldenrod | Asteraceae |
| Eutrochium maculatum | Spotted Joe Pye Weed | Asteraceae |
| Eutrochium purpureum | Sweet-scented Joe Pye Weed | Asteraceae |
© 2004-2009 Michael Hough