This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol3", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
An annual rough-hispid procumbent herb, with alternate entire leaves, or the uppermost sometimes opposite, and small blue or nearly white flowers, short-pedicelled and 1-3 together in the upper axils. Calyx campanulate, unequally 5-cleft, much enlarged and folded together in fruit, the lobes incised-dentate. Corolla tubular-campanulate, 5-lobed, the lobes imbricated. Stamens 5, included, inserted on the corolla-tube; filaments very short. Ovary 4-divided; style short; stigma capitate. Nutlets 4, ovoid, erect, granular-tuberculate, keeled, laterally attached above the middle to the elongated-conic receptacle. [Latin, rough, referring to the leaves.]
A monotypic genus of Europe and Asia.
Asperugo procumbens L. Sp. Pl. 138. 1753.
Stems slender, branched, diffusely procumbent, 6'-18' long, very rough with stiff bristly hairs. Leaves oblong, lanceolate, or the lower spatulate, obtuse or acutish at the apex, 1/2'-1 1/2' long, the lower narrowed into margined petioles; flowers very short-pedicelled, about 1" broad, blue, the pedicels recurved in fruit; fruiting calyx dry and membranous, strongly veined, 4"-6" broad; nutlets obliquely ovoid.