Cacalia.—­Hardy annuals, remarkable for their awkward-looking stems and discoloured leaves.  They grow best in a mixture of sandy loam, brick rubbish, and decomposed dung, well reduced.  They require very little water while growing, and the pots must be well drained.  Cuttings, laid by for a few days to dry, strike readily.  Flower in June.  Height, 1-1/2 ft.

Cactus.—­A sandy loam with brick rubbish and a little peat or rotten manure suits them.  Echinopsis is a good plant for cool houses or windows.  During the summer it should be syringed over-head with tepid water, and weak soot water should be given three times a week.  It is propagated by off-sets planted in sand, also by slicing off a portion from the top of the plant and placing it in light, rich, porous loam.

Caladiums.—­Favourite hothouse foliage plants, generally grown in peat soil at a temperature of 70 degrees.  They require plenty of light while growing, and to be kept moderately moist at the roots.  As the leaves lose colour less water should be given, and during winter they must be kept almost dry.  When fresh growth begins, shake them out of their pots and put them into fresh mould.  In syringing the plants use nothing but the purest rainwater, but the less the leaves are wetted the better for the appearance of the plants.  They may be increased by dividing the root stock into as many pieces as there are crowns.  These should be planted in very rich, sandy soil, an inch or so below the surface.

Calamintha Grandiflora.—­This hardy herbaceous plant has sweetly-fragrant foliage, and bears rose-coloured flowers from May to September.  Any loamy soil suits it, and it is easily increased by suckers.  Height, 1 ft.

Calampelis.—­A species of half-hardy climbing plants of great merit.  They are elegant when in flower, and will endure the open air.  They should be trained to a south wall, or over a vase, or up a pillar.  Any light loamy soil suits them, and they are easily increased by cuttings.  Flower in July.  Height, 10 ft. (See also “Eccremocarpus.”)

Calandrinia.—­Very pretty hardy annuals.  They grow well in sunny places in a mixture of loam and peat, and may be raised from seed sown in the spring or by cuttings placed under hand-glasses.  Bloom in July.  Height, 6 in. to 1 ft.

Calceolaria.—­Many of the varieties are suitable for the greenhouse only.  They may be grown from seed, but as this is so small it should not be covered; and in watering them it is best to stand the seed-pans in water so that the moisture ascends, as watering from the top might wash the seed too deeply into the soil.  July and August are the two best months for sowing.  The half-shrubby kinds make fine bedding plants.  They are easily reared from cuttings.  These are best taken in October.  Put them in light, sandy mould on a well-drained north border; press the earth round them, and cover with a hand-glass.  In very frosty weather a mat should be laid over the glass.  Pot them off in spring; give plenty of air, and plant them out at the beginning of June, or before, if weather permits.