Lysimachia.—The best known is the Creeping Jenny, L. Nummularia, much used for trailing over rockeries and window boxes, with bright yellow flowers. The variety aurea with golden leaves is also popular. Other species that grow from 2 to 3 ft. high, and are good border plants, are L. clethroides, with white spikes of flowers; L. vulgaris, L. thyrsiflora, L. ciliata, L. verticillata and L. punctata, all yellow.
Malva.—M. moschata, 2 ft., with a profusion of pale pink or white flowers, and musky deeply cut leaves, though a British plant, is worth introducing to the flower borders when the soil is light and free.
Meconopsis.—The Welsh poppy, M. cambrica, 1 to 2 ft. high, yellow, and M. Wallichi, from the Himalayas, 4 to 6 ft. high with pale blue flowers, are the best known perennials of the genus. The last-named, however, is best raised from seeds every year, and treated like the biennial kinds.
Mertensia.—M. virginica, 1 to 1½ ft., azure blue, shows flowers in drooping panicles in May and June. It does best in shady peat borders.
Mimulus.—Monkey-flower. Free-blooming, showy scrophulariaceous plants, thriving best in moist situations. M. cardinalis, 2 to 3 ft., has scarlet flowers, with the limb segments reflexed; M. luteus and its many garden forms, 1 to 1½ ft., are variously coloured and often richly spotted; and M. cupreus, 8 to 10 in., is bright coppery-red. M. moschatus is the Musk-plant, of which the variety Harrisoni is a greatly improved form, with much larger yellow flowers.
Monarda.—Handsome labiate plants, flowering towards autumn, and preferring a cool soil and partially shaded situation. M. didyma, 2 ft., scarlet or white; M. fistulosa, 3 ft., purple; and M. purpurea, 2 ft., deep purple, are good border flowers.
Muscari.—Pretty dwarf spring-flowering bulbs. M. botryoides (Grape Hyacinth), 6 in., blue or white, is the handsomest; M. moschatum (Musk Hyacinth), 10 in., has peculiar livid greenish-yellow flowers and a strong musky odour; M. monstrosum (Feather Hyacinth) bears sterile flowers broken up into a feather-like mass. Good garden soil.
Myosotidium nobile.—A remarkable plant, 1½ to 2 ft. high, with large blue forget-me-not-like flowers. Requires gritty peat soil and cool situations, but must be protected from frost in winter.
Myosotis.—Forget-me-not. Lovely boraginaceous plants. M. dissitiflora, 6 to 8 in., with large, handsome and abundant sky-blue flowers, is the best and earliest, flowering from February onwards; it does well in light cool soils, preferring peaty ones, and should be renewed annually from seeds or cuttings. M. rupicola, 2 to 3 in., intense blue, is a fine rock plant, preferring shady situations and gritty soil; M. sylvatica, 1 ft., blue, pink or white, used for spring bedding, should be sown annually in August.
Narcissus.—See [Narcissus].