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 very large genus of undershrubs and herbs of diverse habit. Calyx tubular-bilabiate, upper lip entire or tridentate, lower bifid; throat naked. Corolla bilabiate; throat naked, hairy or tuberculate; upper lip erect, entire or bifid; lower lip trilobate, lateral lobes spreading. Stamens 2; anther-cells distant, one fertile and the other sterile. Nutlets usually smooth and shining. The number of species is estimated at '400. They are found in most temperate and tropical countries, and are particularly numerous in the warmer parts of America. We have two indigenous species, one, S. Verbenaca, being tolerably common. This has small violet-blue flowers remark-able for the short upper lip of the corolla. S. pratensis has conspicuous bright blue flowers, but it is exceedingly rare in Britain, and probably an introduced plant, as it has long been cultivated in gardens. The generic name is from salvare, to save, from the reputed medicinal properties of some species.
1. S. patens (fig. 198). - This splendid perennial plant is not perfectly hardy, but very desirable on account of the intense rich blue of its velvety flowers. Unfortunately it is of rather straggling habit. It is a native of Mexico.
2. S, chionantha. - An erect perennial about 2 feet high with oblong-oval shaggy leaves and very handsome spikes of large pure white flowers, appearing towards the end of Spring. Native of Asia Minor.
3. S. verticillaia. - This is a robust species from 3 to 4 feet high. Leaves ovate- or somewhat triangular-cordate at the base and irregularly toothed or lobed. Flowers blue, numerous, in long whorled spikes. Corolla-tube naked. A very hardy species from Central Europe, blooming in July and August.
4. S. glutinosa. - An-other hardy European species about a yard high, the younger parts clothed with glandular viscid hairs. Leaves cordate-hastate, acuminate, coarsely serrate. Flowers pale yellow spotted with brown, about six in a cluster. Corolla-tube naked. This blooms from June to August.
5. S. splendens. - A tender shrubby species with ovate-crenate gla-brescent leaves on long petioles and bright scarlet flowers remark-able for the coloured calyx. South America.
6. S. Forskoehlii. - This is a hardy herbaceous species with rather naked stems about a foot high, and tufted radical hairy obovate auricled leaves, and purple, blue or violet and white flowers, produced all the Summer. A native of the Levant.
S. argentea has fine large ovate leaves clothed with a beautiful silvery down, and white flowers of short duration. South Europe. S. bicolor is a tall species from North Africa, with white and violet flowers. S. coccinea, a native of South America, has small bright scarlet flowers. S. bracteata has small purple flowers and conspicuous coloured bracts; it is a native of Russia. S. Horminum is another species with coloured bracts and blue flowers, from the Pyrenees.
Fig. 198. Salvia patens. (1/4 nat. size.)