Buckwheats provide color spring and summer. Eriogonum umbellatum (sulphur buckwheat) sports bright yellow flowers in spring. Eriogonum giganteum (St. Catherine’s Lace) is topped with creamy clusters of flower sprays reaching as high as five feet. The star of the genus, Eriogonum grande var. rubescens (rosy buckwheat) displays rosy buttons atop rounded gray-green leaves for most of the summer.