It is a "helianthemum" of the Sunflower tribe.
"Herbal Simples Approved for Modern Uses of Cure"
William Thomas Fernie
See Nesaea, helianthemum formosum, halimifolium, laevipes, lasianthum, lavendulaefolium, libanotis, pilosum, polifolium, pulverulentum, serpyllifolium, umbellatum, vulgare, vulgare nummularium, vulgare barbatum, vulgare mutabile, vulgare grandiflorum, vulgare ovalifolium, vulgare hysopifolium, Hemp Tree, Hippophae rhamnoides, Holboellia latifolia, Holly, the, Honey Locust, Honeysuckles, Hop tree, Hornbeam, Horse Chestnut, Hortensia opuloides, Humming Bird's Trumpet, Hybiscus syriacus, syriacus vars.
"Hardy Ornamental Flowering Trees and Shrubs"
A. D. Webster