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 large genus of very ornamental annual or perennial plants, rarely frutescent. Leaves 5- to many-foliolate, rarely trifoliolate; stipules adnate to the base of the long petiole. Flowers variable in colour, blue lilac yellow or white, in terminal racemes. Calyx 2-lipped. Wing petals connate at the tips; keel terminating in a curved beak. Pod flat, coriaceous or fleshy. Upwards of eighty species have been described, chiefly from temperate North America, a few tropical, and a few species from the Mediterranean region. From lupus, a wolf or destroyer, though the application is not clear. Very few of the species are in general cultivation, but a great many handsome varieties have resulted from intercrossing.
1. L. polyphyllus (fig. 66). - Herbaceous, about 5 or 6 feet high, leaflets very numerous, with immense racemes of usually dark blue flowers, though variable in this respect, and often with a mixture of white. This is the commonest and at the same time one of the best species in cultivation. Native of North-western America.
2. L. mutabilis. - A rather tender herbaceous species, from the Andes of Bogota. A strong-growing plant about a yard high. Leaflets 7 to 9, linear-lanceolate. Flowers very fragrant like the Sweet Pea, variable and changeable in colour, when first open nearly white, and at length with tinges of yellow and purple.
3. L. tomentosus. - A beautiful hirsute species; leaflets 5 to 9, lanceolate. Flowers variable: pink, white, yellow, purple, blue, in different hues and combinations. Andes of Peru.
Fig. 66. Lnpinus polyphyllus. (1/2 nat. size.)
4. L. luteus. - A dwarf species with bright yellow fragrant flowers, from the Mediterranean region.
5. L. nanus. - This is the common Dwarf Annual Lupine, with 5 to 7 narrow lanceolate acute hairy leaflets and normally lilac and blue flowers. There are, however, variously coloured varieties of this and L. afflnis, including white, yellow, various shades of violet and blue in different combinations. A native of California.
6. L. varius. - A Mediterranean species with variable but usually dark blue flowers.
Many more species might be included, but this would serve no useful purpose, especially as there is great confusion in the nomenclature.