Alstromeria (Peruvian Lilies).—­These beautiful summer-flowering hardy perennials produce large heads of lily-like blossoms in great profusion, which are invaluable for cutting for vase decorations as the bloom lasts a long time in water.  Plant in autumn 6 in. deep in a well-drained sunny situation, preferably on a south border.  Protect in winter with a covering of leaves or litter.  They may be grown from seed sown as soon as it is ripe in sandy loam.  They bloom in July.  Height, 2 ft. to 3 ft.

Alternantheras.—­Cuttings of this greenhouse herbaceous plant may be struck in autumn, though they are usually taken from the old plants in spring.  Insert them singly in 4-1/2-in. pots filled with coarse sand, loam, and leaf-mould.  When rooted, place them near the glass, and keep the temperature moist and at 60 degrees or 65 degrees, then they will flower in July.  Height, 4 in. to 1 ft.

Althea—­See “Hibiscus.”

Alyssum.—­Well adapted for rock-work or the front of flower-beds, and is best sown in autumn.  The annual, or Sweet Alyssum, bears an abundance of scented white flowers in June, and on to the end of September.  The hardy perennial, Saxatile (commonly called Gold Dust), bears yellow flowers in spring.  Height, 6 in.

Amaranthus.—­The foliage of these half-hardy annual plants are extremely beautiful, some being carmine, others green and crimson, some yellow, red, and green.  They are very suitable either for bedding or pot plants.  Sow the seed early in spring in gentle heat, and plant out in May or June in very rich soil.  If put into pots, give plenty of room for the roots and keep well supplied with water.  Flower in July and August.  Height, 1-1/2 ft. to 6 ft.

Amaryllis.—­These plants bear large drooping bell-shaped lily-like blossoms.  They thrive best in a compost of turfy loam and peat, with a fair quantity of sand.  The pots must in all cases be well drained.  Most of the stove and greenhouse species should be turned out of their pots in autumn, and laid by in a dry place until spring, when they should be re-potted and kept liberally supplied with water.  A. Reticulata and A. Striatifolia bloom best, however, when undisturbed.  Discontinue watering when the foliage shows signs of failing, but avoid shrivelling the leaves.  The hardy varieties should be planted 6 in. deep in light, well—­drained soil, and allowed to remain undisturbed for two or three years, when they will probably require thinning out.  They are increased by off-sets from the bulbs.

The Belladonna (Belladonna Lily) should be planted in June in a sheltered border in rich, well-drained soil.

Formosissima (the Scarlet Jacobean Lily) is a gem for the greenhouse, and very suitable for forcing, as it will bloom two or three times in a season.  It should be potted in February.

Lutea (Sternbergia) flowers in autumn.  Plant 4 in. deep from October to December.