This section is from the book "Handbook Of Hardy Trees, Shrubs, And Herbaceous Plants", by W. Botting Hemsley. Also available from Amazon: Handbook of hardy trees, shrubs, and herbaceous plants.
A monotypic genus from North America. Flower-heads large, terminal, solitary. Outer bracts of the involucre spinytoothed, the inner ciliated. Receptacle naked, fleshy. Outer florets largest. Pappus of one row of membranous scales, nearly equalling the corolla. Named in honour of an English botanist.
1. S. cyanea. - Stem herbaceous, covered with a close cottony down, glaucescent, about 2 feet high. Leaves sessile, alternate, lanceolate, acute, with a few spiny teeth near the base; lower ones much longer. Flowers blue, glandular, produced in September. A native of Carolina, and rather tender.