 Hieracium venosum (Rattlesnake-Weed) |
 Hordeum jubatum (Squirrel-Tail Grass) |
 Houstonia caerulea (Common Bluets) |
 Houstonia longifolia (Long-Leaved Houstonia) |
 Houstonia serpyllifolia (Creeping Bluets) |
 Hybanthus concolor (Green Violet) |
 Hydrangea arborescens (Wild Hydrangea) |
 Hydrastis canadensis (Goldenseal) |
 Hydrocotyle americana (American Water-Pennywort) |
 Hydrocotyle umbellata (Umbellate Water-Pennywort) |
 Hydrophyllum appendiculatum (Appendaged Waterleaf) |
 Hydrophyllum canadense (Broad-Leaved Waterleaf) |
 Hydrophyllum virginianum (Virginia Waterleaf) - Dark Purple Flowers |
 Hydrophyllum virginianum (Virginia Waterleaf) - Light Purple Flowers |
 Hydrophyllum virginianum (Virginia Waterleaf) - White Flowers |
 Hypericum ascyron (Great St. Johnswort) |
 Hypericum canadense (Lesser Canadian St. Johnswort) |
 Hypericum densiflorum (Bushy St. Johnswort) |
 Hypericum ellipticum (Pale St. Johnswort) |
 Hypericum hypericoides (St. Andrew's Cross) |
 Hypericum mutilum (Dwarf St. Johnswort) |
 Hypericum prolificum (Shrubby St. Johnswort) |
 Hypericum punctatum (Spotted St. Johnswort) |
 Hypopitys monotropa (Pinesap) |
 Hypoxis hirsuta (Yellow Stargrass) |
 Ilex montana (Mountain Winterberry) |
 Ilex mucronata (Catberry) |
 Ilex verticillata (Common Winterberry) |
 Impatiens capensis (Spotted Jewelweed) |
 Impatiens pallida (Pale Jewelweed) |
 Impatiens pallida (Pale Jewelweed) - Pale Flower |
 Iodanthus pinnatifidus (Purple Rocket) |
 Ionactis linariifolia (Stiff Aster) |
 Ipomoea pandurata (Wild Potato Vine) |
 Iris cristata (Dwarf Crested Iris) |
 Iris lacustris (Dwarf Lake Iris) |
 Iris versicolor (Large Blue Flag) - Side View |
 Iris versicolor (Large Blue Flag) - Top View |
 Iris virginica (Virginia Iris) |
 Isotria verticillata (Large Whorled Pogonia) |
 Jeffersonia diphylla (Twinleaf) |
 Juglans cinerea (Butternut) - Female Flowers |
 Juglans cinerea (Butternut) - Male Flowers |
 Juncus acuminatus (Sharp-Fruited Rush) |
 Juncus balticus (Baltic Rush) |
 Juncus brachycephalus (Small-Headed Rush) |
 Juncus effusus (Soft Rush) |
 Juncus tenuis (Path Rush) |
 Juncus torreyi (Torrey's Rush) |
 Justicia americana (American Water-Willow) |