This section is from the book "Commercial Gardening Vol2", by John Weathers (the Editor). Also available from Amazon: Commercial Gardening, A Practical & Scientific Treatise For Market Gardeners.
This large genus includes many plants of garden value, all easily grown, and suitable for rock gardens, old walls, etc, like the common Toad Flax (L. vulgaris). Among the dwarfer kinds 2 to 9 in. high are alpina, purple and orange, with a rose-coloured variety; anticaria, white and lilac; antirrhinifolia, forms dense masses with bright-purple flowers; Cymbalaria (the Kenilworth Ivy), a well-known British wall plant with purple, lilac, and white-flowered varieties; hepaticoefolia, a carpeting plant about 2 in. high, with lobed leaves and lilac-purple flowers; origanifolia, 9 in., deep blue and yellow; pallida, 3 in., violet purple; triornithophora, 6 in., violet. The taller kinds include genistoe-folia, 4 ft., sulphur yellow; dalmatica, 2-4 ft., pale yellow, to which macedonica is closely related; purpurea, 2 ft, purple; and vulgaris, 1-2 ft., yellow, with a charming regular-flowered variety called peloria. All kinds grow in any good gritty soil, and are increased by seeds and division. There are several annual species also.