Redbay Redbud (spp.)
Redbud 'Appalachia' Redbud 'Forest Pansy'
Redbud 'Silver Cloud' Redbud 'Wither's Pink Charm'
Redbud, Afgan Redbud, Eastern (spp.)
Redbud, Eastern 'Appalachia' Redbud, Eastern 'Forest Pansy'
Redbud, Eastern 'Silver Cloud' Redbud, Eastern 'Wither's Pink Charm'
Redbud, Griffith's Redbud: siliquastrum
Redflower Cactus Redflower Cactus: lindheimeri
Redleaf Rose 'Redspire' Callery Pear
Red-White-and-Blue Flower (spp.) Redwood, California (spp.)
Redwood, California 'Filoli' Redwood, California 'Prostrata'
Redwood, California 'Soquel' Redwood, Coast (spp.)
Redwood, Coast 'Filoli' Redwood, Coast 'Prostrata'
Redwood, Coast 'Soquel' Redwood, Giant (spp.)
Redwood, Sierra (spp.) Reed, Bur
Regal Geranium 'Martha Washington' 'Regal Robe' Alumroot: Heuchera
'Regent' Saskatoon Serviceberry 'Regina' Alumroot: Heuchera
'Repens' Willowleaf Cotoneaster 'Rheingold' American Arborvitae
Rhododendron, Catawba (spp.) Rhododendron, Catawba 'Boursault'
Rhododendron, Catawba White Rhododendron, Great (spp.)
Rhododendron, Great 'Golden Lights' Rhododendron, Great 'Great Laurel'
Rhododendron, Great 'Mandrin Lights' Rhododendron, Rosebay (spp.)
Rhododendron, Rosebay 'Golden Lights' Rhododendron, Rosebay 'Great Laurel'
Rhododendron, Rosebay 'Mandrin Lights' Rhubarb, Giant
'Right On' Daylily 'Ring of Fire' Common Sunflower
'Rio Samba' Rose River Birch (spp.)
River Birch 'Summer Cascade' River Birch: nigra minor
'River Hawk' Tall Bearded German Iris River Jam
River Maple (spp.) River Maple 'Beebe'
River Maple 'Pyramidale' River Maple 'Silver Queen'
River Maple 'Skinneri' River Maple 'Wieri'
River Oats 'Robin (Songbird Series)(n)' Columbine
'Robin Hill' Apple Serviceberry 'Robinson' Flowering Crabapple
Robust Acacia Rock Anise Hyssop
Rock Maple (spp.) Rock Maple 'Ann Rutledge'
Rock Maple 'Arrowhead' Rock Maple 'Coleman'
Rock Maple 'Commemoration' Rock Maple 'Eagle Claw'
Rock Maple 'Endowment' Rock Maple 'Globosum'
Rock Maple 'Goldspire' Rock Maple 'Legacy'
Rock Maple 'Newton Sentry' Rock Maple 'Seneca Chief'
Rock Maple 'Skybound' Rock Maple 'Sweet Shadow'
Rock Maple 'Temple's Upright' 'Rocket City' Daylily
Rockspray Cotoneaster (spp.) Rocky Mountain Columbine (spp.)
Rocky Mountain Maple Rocky Mountain Pinyon
Rocky Mountain Pinyon Pine Rocky Mountain Sage
Rocky Mountain White Pine (spp.) Rocky Mountain White Pine Blue
Roman Cassie Roman Wormwood
'Rosa Plea' Dwarf Flowering Almond