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.
Herbs or undershrubs with toothed leaves and terminal racemes or spikes of flowers. Calyx nearly equally 5-toothed. Corolla-tube not dilated at the throat; and usually furnished with a ring of hairs inside; upper lip erect or spreading; lower lip longer, 3-lobed, the lateral lobes often reflexed. Stamens 4, the lower pair longer. This is a large genus, numbering nearly 150 species; found in temperate and warm regions. The name is from an ear or spike, the form of the inflorescence. There are several native species. S. Betonica, Wood Betony, is a common plant in England. It is a tall herb with dense terminal bracteate spikes of reddish purple flowers. S. sylvatica and S. palustris are also tolerably common.
1. S. landta. - This is the species employed in bedding for its tufted silvery foliage, which is densely clothed with a silky tomentum. The flowers are small and inconspicuous. A native of South-eastern Europe and Asia Minor.
S. coccinea is a South American species about 3 feet high, with cordate toothed hairy leaves and brilliant scarlet flowers in spikes of whorls.