The Genus Lamium
Common Deadnettle, Common Dead-nettle, Girafehead, Henbit, Henbit Deadnettle: Lamium amplexicaule (Synonym: Lamium amplexicaule var. album) - Leaves found directly below the flower clusters mostly sessile and clasping, not purple-tinged. Corolla entirely glabrous within.
Red Deadnettle, Purple Deadnettle, Red Dead-nettle: Lamium purpureum var. purpureum - Leaves all at least short-petiolate with the cluster of upper leaves beneath the flowers purple-tinged. Corolla with a ring of hairs inside near the base.