- Name: Green Gold Bupleurum - Other Common Names: Hare's Ear / Hound's Ear / Thorowax / Thoroughwax - Scientific Name: Bupleurum Griffithii Syn. Bupleurum Rotundifolium - Color: Yellowish Flowers With Blue-Green Round Leaves - Plant Seeds: Outdoors After Frost / Indoors Weeks Before Last Frost - Bloom Time: Summer - Hardiness Zone: N/A (But Reseeds Itself Easily, So It Acts Like A Perennial In All Zones) - Plant Height: 24 - 32" - Plant Spacing: 12 - 15" - Light Requirements: Sun - Part Shade - Soil & Water Preferences: Average - Quantity: 100 - Other: Besides Having A Fun Name (Just Try To Say It 10 Times Fast!) Bupleurum Is An ‘Everlasting’ Flower, So It Is Excellent For Fresh Cut Or Dried Arrangements.