AGERATUM (from a, not, and geras, old; in reference to the flowers being always clear). SYN. Caelestina. ORD. Compositae. This genus includes several American species, for the most part half-hardy annuals and biennials; or, if the seed is not allowed to ripen, they become perennials. Involucre cup-shaped, of many imbricated linear bracts; receptacle naked. Leaves opposite. A light rich soil is most suitable. Very easily increased by cuttings or seeds; if required true, the former is the only sure method of propagation. To grow large plants for greenhouse decoration, sow the seeds in January, in heat, in sandy soil, barely covering them. As soon as the young plants are large enough, prick them off into thumb pots, and keep in heat till they grow freely, then place them into a cooler house. Transfer into larger pots as soon as the others are full of roots, until they are finally shifted into 10in. or 12in. pots. When these are full of roots, the plants should be watered with liquid manure twice a week, and they soon flower well, making fine specimens. During hot weather especially, they should be well syringed with clear water daily, to keep down red spider. The plants required for bedding (for which purpose the dwarf garden varieties are mostly used) should be raised about the same time, kept in small pots, gradually hardened off, and planted out in the middle or end of June. Cuttings of all the varieties strike readily in heat, treated like most soft-wooded plants, and, when rooted, may be managed as recommended for the seedlings. AGERATUM Lasseauxii (Lasseaux's). fl.-heads rose-coloured, small, disposed in corymbose heads. Summer. l. lanceolate-elliptic. h. 1 1/2ft. to 2ft. Monte Video, 1870. A much-branched plant, requiring greenhouse protection in winter, and suitable for planting out in summer. AGERATUM latifolium (broad-leaved). A synonym of Piqueria latifolia. AGERATUM mexicanum (Mexican).* The commonest and most useful species, with a profusion of lilac-blue flowers. h. 2ft. Mexico, 1822. When used for bedding purposes it may be pegged down like the Verbena, or be allowed to grow its full height. Several very dwarf varieties of it have originated under cultivation, which supersede the species for bedding, the best of which are:-CUPID,* rich blue, very dwarf and floriferous; IMPERIAL DWARF, about 9in. high, with porcelain blue flowers; LADY JANE, of the same colour, very free; QUEEN,* silvery grey, about 9in. high; SNOWFLAKE,* white, very free and showy; SWANLEY BLUE,* very deep blue, 6in. to 8in. high. There is also a white-flowered variety of Mexicanum, which is very showy; and a variegated form, sometimes grown for the sake of its pretty foliage. AGERATUM Wendlandi (Wendland's). fl. blue, with rosy reflections, produced in abundance. l. cordate, dark green. Stems hairy. Mexico, 1885. A dwarf, compact species.