Coix Lachryma (_Job's Tears_).--A half-hardy, annual, ornamental grass bearing clusters of beautiful pearl-like seeds. Sow in a warm spot in April, barely covering the seed with fine soil, and keep the surface of the ground moist till germination is ensured. Height, 1-1/2 ft. Colchicum (_Autumn-Flowering Crocus_).--Plant the bulbs in February in light, loamy soil, placing them 2 in. deep and 3 in. apart. They are readily increased by off-sets from the bulb. September is their flowering season. Height, 3 in. (_See also_ "Bulbocodium.") Coleus.--Tender perennial shrubs of some merit, requiring the protection of a greenhouse. Keep the plants root-bound and near the glass, with a good supply of heat and moisture. They succeed best in a mixture of loam and peat. Cuttings of shoots 3 in. long planted in sand, covered with a glass, and plunged in heat 60 to 70 degrees, will strike. Pot off singly in loam and sand. Bloom in June or July. Height, 2 ft. to 3 ft. Colletia.--Ornamental evergreen shrubs. A mixture of peat and loam, with a sheltered position, is their delight. Cuttings will strike in sand if covered with glass. They produce their flowers in July. Height, 2 ft. to 3 ft. Collinsia.--Most elegant hardy annuals, doing well in any garden soil. The seed is sown in autumn for early flowering, and in spring for a later display. Bloom May to August. Height, 1 ft. Collomia.--Hardy annuals, possessing little beauty. Treat as Collinsia. Flower in July. Height, 1 ft. to 2 ft. Colt's-foot.--This hardy perennial flowers before the leaves appear. It grows best in a moist, clayey soil, and may be increased by pieces of the running root. Columbine.--_See_ "Aquilegia." Colutea Arborescens (_Bladder Senna_).--A shrub with Acacia-like leaves and producing yellow Pea-shaped flowers in July, followed with bladder-shaped seed vessels. It will grow in any soil, and may be raised either from seed or cuttings taken in autumn. Height, 10 ft. Commelina Sellowina (_Blue Spider Wort, or Day Flower_).--A pretty greenhouse climber, bearing cobalt-blue flowers. It should occupy a sunny position, and be watered freely from March to September, after which very little should be given. Commelina Tuberosa.--Perfectly hardy plants, bearing in June blue or white flowers the size of a shilling. The bulbs may be planted in spring in any garden soil; the plants are increased by off-sets. Height, 1-1/2 ft.