Alyssum
(from a, not, and lyssa, rage; in reference to a fable that the plant allayed anger). Madwort. Including Psilonema, Ptilotrichum, Schivereckia. ORD. Cruciferae. Annuals or dwarf, branching, shrubby perennials, often clothed with hoary, stellate hairs. Flowers small, cruciform, white or yellow. Leaves distant, or the radical ones tufted, usually entire. Several of the species are very much alike. They are excellent plants for the rockery, or for the front of borders, growing freely in common but well-drained garden soil. They may be increased by cuttings, by division of the roots, or by seed. The cuttings should be made from young shoots, 2in. to 3in. in length, inserted in sandy loam, early in the season, in a shady place. Seed may be raised outside, or in a frame in pans in sandy soil, most of them germinating in two or three weeks.
A. alpestre (alpine).* fl. yellow; raceme simple. June. l. obovate, hoary. Stem rather shrubby at the base, diffuse, greyish. h. 3in. South Europe, 1777. Perennial. A very neat little tufted species. A. argenteum (silvery), A. Bertolonii (Bertoloni's), and A. murale (wall), are larger growing species allied to the above, but of less cultural merit.
A. a. obtusifolium (obtuse-leaved). fl. yellow, corymbose. June. l. obovate-spathulate, blunt, silvery on the under surface. h. 3in. Tauria, 1828. A rare alpine.
A. atlanticum (Atlantic). fl. yellow; raceme simple. June. l. lanceolate, hoary, and pilose. Stems shrubby at the base, erect. h. 6in. to 1ft. South Europe, 1820. A. Marschallianum is intermediate between A. alpestre and A. a. obtusifolium, but is seldom met with under cultivation.
A. gemonense (German).* fl. yellow, in close corymbs. April to June. l. lanceolate, entire, greyish-velvety from stellate down. Stem shrubby at the base. h. 1ft. Italy, 1710. Closely allied to A. saxatile, but not so hardy; it is very desirable for rockeries.
A. macrocarpum (large-fruited). fl. white, racemose. June. l. oblong, blunt, silvery. Stem shrubby, branched, somewhat spiny. h. 8in. South of France, 1828. A. spinosa (thorny), and A. halimifolia (purslane-leaved), are very like this species. A. dasycarpum (thick-fruited) is an annual with yellow flowers.
A. maritimum. See Koeniga.
A. montanum (mountain). fl. yellow, sweet-scented; raceme simple. May to July. l. somewhat hoary; lower ones obovate; upper ones oblong. Stems rather herbaceous, diffuse, pubescent. h. 2in. or 3in. Europe, 1713. A distinct and charming species for the rockery, forming compact tufts of slightly glaucous green. A. cuneifolium (wedge-leaved), A. diffusum (diffuse), and A. Wulfenianum (Wulfenius) come close to this species, the latter being the most desirable.
A. olympicum (olympian). fl. deep yellow, small, in roundish corymbose heads. Summer. l. spathulate, sessile, very small, greyish. h. 2in. to 3in. Northern Greece.
A. orientale (Oriental).* fl. yellow, corymbose. May. l. lanceolate, repandly-toothed, waved, downy. Stems suffruticose at the base. h. 1ft. Crete, 1820. There is a variety with variegated leaves.
A. saxatile (rock).* fl. yellow, in close corymbose heads. April. l. lanceolate, entire, clothed with hoary tomentum. Stems shrubby at the base. h. 1ft. Eastern Europe, 1710. A very common and showy spring plant.
A. s. variegatum (variegated).* A constant and prettily variegated form, which is even more handsome than the type. On the rockery it does well, as it requires a sunny, well drained, position.
A. serpyllifolium (Thyme-leaved).* fl. pale yellow, in simple racemes. April to June. l. very small, 1/4in. to 1/2in. long, ovate, scabrous, hoary. h. 3in. to 4in. Branches spreading, sub-woody at the base. South Europe, 1822.
A. tortuosum (twisted). fl. yellow; raceme corymbose. June. l. hoary, somewhat lanceolate. Stem shrubby at the base, twisted, diffuse. h. 6in. Hungary, 1804.
A. Wiersbeckii (Wiersbeck's).* fl. deep yellow, in close corymbose heads, about 1 1/2in. across. Summer. l. 2in. long, oval-oblong-pointed, sessile, attenuated at the base, roughish and hairy. Stems erect, scabrous, simple, rigid. h. 1 1/2ft. Asia Minor.