'Iron Butterfly' Foamflower: Tiarella 'Iron Butterfly' Narrow Leaf Ironweed
Iron Cross Begonia Iron Fern
Ironbark, Broad-leaved Ironbark, English Silver-leaved
Ironbark, Narrow-leaved Ironbark, Pink (spp.)
Ironbark, Pink 'Rosea' Ironbark, Red (spp.)
Ironbark, Red 'Rosea' Ironbark, White
Ironbark: leucoxylon megalocarpa, White Ironweed, Narrow Leaf 'Iron Butterfly'
Ironweed, New York Ironwood
Ironwood Box Ironwood, Black
Ironwood, Brazillian Ironwood, Desert
Ironwood, Persian Ironwood, Red
Ironwood, Southern Ironwood, Southsea
Ironwood: capensis, Black Ironwood: caroliniana
Ironwood: confusa Ironwood: paniculata
Ironwood: tesota Ironwood: undulata, White
'Iroshidori' Hybrid Hydrangea: hybrid 'Irvine Currant' Florist's Chrysanthemum
'Irvine Dark Bronze' Florist's Chrysanthemum 'Irvine Pink' Florist's Chrysanthemum
'Irvine Red' Florist's Chrysanthemum 'Irvine Regal' Florist's Chrysanthemum
'Irvine Yellow' Florist's Chrysanthemum 'Isabelle Pring' Waterlily
'Iseli Fastigiata' Colorado Spruce 'Iseli Foxtail' Colorado Spruce
Island Alumroot 'Island Brocade' Broadleaf Sedge
Island Bush Snapdragon 'Island Charm' Hosta
'Island Delight' Daylily Island Gooseberry
Island Oak Island Sagebrush
Island Shrub Mallow Island Tree Poppy
Islay 'Isle of Capri' Oleander
Isoplexis Isotome, Rock
'Issai' Purple Beautyberry Italian Arum (spp.)
Italian Arum 'Pictum' Italian Buckthorn (spp.)
Italian Buckthorn (spp.) Italian Cypress (spp.)
Italian Cypress 'Stricta' Italian Cypress 'Swaine's Gold'
Italian Maple Italian Stone Pine
Italian Yellow Jasmine 'Italica' Black Poplar
'Itami nishiki' Japanese Maple Itswili
Ivory Pineapple (spp.) Ivory Pineapple Variegated
'Ivory Queen' Gallberry Holly 'Ivory Silk' Japanese Tree Lilac
Ivy Geranium (spp.) Ivy Geranium 'Colorcade Lavender'
Ivy Geranium 'Sunset' Ivy Leaf Maple
Ivy Leaf Maple: cissifolium Ivy Leaf Morning Glory 'Roman Candy'
Ivy Palm, Australian (spp.) Ivy Palm, Australian 'Amate™'