'Umbracalifera' American Arborvitae 'Umbraculifera' Common Horsechestnut
'Umbraculifera' Eastern White Pine 'Umbraculifera' Smoothleaf Elm
Umbrella Arum (spp.) Umbrella Bamboo
Umbrella Bamboo: spathiflorus Umbrella Bamboo: spathiflorus crassinodus
Umbrella Magnolia Umbrella Pine
Umbrella Pine: pinea Umbrella Pine: verticillata
Umbrella Plant (spp.) Umbrella Plant, Dwarf Variegated
Umbrella Plant: alternifolius Umbrella Plant: hybrid
Umbrella Sedge Umbrella Thorn
Umbrella Tree Umbrella Tree (spp.)
Umbrella Tree 'Amate™' Umbrella Tree, Queensland (spp.)
Umbrella Tree, Queensland 'Amate™' Umsenge
Underwater Rose 'Undulatum' Norway Maple
'Unforgettable Fire®' Burning Bush 'Unicorn' American Arborvitae
Unicorn Plant 'Unique' Panicle Hydrangea
'Universal Orange Plus' Pansy Upright Bugleweed (spp.)
Upside Down Fern 'Urban' Hybrid Elm
Urn Plant Bromeliad 'Samuri' Urn Plant (spp.)
Urn Plant 'Primera' Urn Plant 'Silver Vase'
Urn Plant 'Super Auslese' Urn Plant: ssp.
Urumiensis Tulip Ussurian Pear
Utah Juniper Uverillo
'Uzu Azisai' Bigleaf Hydrangea 'V-14 Pink' Poinsettia
'V-17 Angelika White' Poinsettia 'Vaired Direction' Larch
'Valentine Day' Japanese Camellia 'Valentine Heart' Rose
'Valentine Lace' Hosta Valerian
Valerian, Eastern Valerian, Greek (spp.)
Valerian, Red (spp.) Valerian, Red 'Coccineus'
Valerian: reptans, Greek 'Valley Cushion' Mugo Pine
'Valley Forge' American Elm Valley Oak
'Valley Rose' Japanese Pieris Vallonea Oak
Vallonea Oak: ithaburensis 'Van Houttei' Scarlet Sage: splendens
Vanda Orchid 'Vandenberg' Santa Barbara Ceanothus
Vanhoutte Spirea (spp.) Vanhoutte Spirea 'Renaissance'
Vanhoutte's Brazil Sage (spp.) 'Vanilla Butterfly®' Marguerite Daisy
'Vanilla' Cottage Pink Vanilla Plant
'Vanilla Spice™' Summer Sweet 'Vanitie' Tall Bearded German Iris