CALABA-TREE. See [Calophyllum Calaba.]

CALADENIA (from kalos, beautiful, and aden, a gland; in reference to the disk of the labellum being finely beset with glands). ORD. Orchideæ. A genus of pretty greenhouse terrestrial orchids from New Zealand and Australia. They should be kept in a cool frame or greenhouse, and carefully watered, when not in a growing state. A compost of peat, loam, and sand, in equal parts, suits them well. Over thirty species are enumerated, but probably none are seen out of botanic gardens.

CALADIUM (derivation of name doubtful; probably of Indian origin). ORD. Aroideæ. Stove perennials, chiefly grown for the great beauty and varied hue of their leaves. Spathe hood-like, rolled round at the base; spadix, upper portion entirely covered with stamens, but ultimately becoming bare at the extreme top, provided with blunt glands or sterile stamens in the middle, and ovaries beneath; anthers shield-shaped and one-celled; ovaries numerous, two-celled, with from two to four ascending ovules in each cell. Leaves upon long petioles, more or less sagittate, ovate, and usually very richly coloured. Fruit a one or two-celled berry, with few seeds. They are all of easy culture, and grow freely in a humid atmosphere. In March, when the tubers have been kept dry or rested for some time, they may be started into growth again, in small pots, placed in a stove or pit, where a night temperature of from 60deg. to 65deg. is maintained, and syringed daily once or twice at least. As soon as indications of activity are presented, they may be shifted into 4in., 5in., or 6in. pots, or larger ones may be used if good sized specimens are required. If the tubers should be in large pots, it is best to turn them out, dividing if necessary, and placing all the crowns in small pots, from which they can be removed when root action and growth are resumed, and they require more room. Large tubers, if sound, may be divided, and the pieces placed in pots of such sizes as it is desired to grow them in.

Soil. Turfy loam, leaf mould, turfy peat, and a little well decomposed manure, in equal parts (not broken up too fine), with a good sprinkling of sharp sand, form an excellent compost, the whole being well incorporated together. Thorough drainage must be insured, as these plants require an abundance of water. After potting, they should be placed in a stove temperature, and kept well moistened by syringing two or three times daily. If accommodated with mild bottom heat at this time, they will make much freer and more vigorous growth than if otherwise treated. Water sparingly at first, but as soon as the leaves expand, increase the supply; and, when the pots are well filled with roots, apply clear liquid manure at every other time of watering. As the season advances, the temperature and humidity of the house should be increased. During bright sunshine, Caladiums should be slightly shaded for a few hours in the middle of the day, with some thin material, just to break the fierceness of the sun's rays; but the more they are exposed to the light at other times during growth, the brighter, richer, and more beautiful will the foliage be. As soon as the plants have attained a good size, some of them should be placed in the coolest part of the house, and partially hardened off; they may then be taken to the conservatory, allowing them a situation free from currents of cold air, and giving water only when really necessary. They may remain here for some time, but care must be taken to return them to the stove before they suffer from cold.

Small neatly grown specimens make beautiful ornaments for table decoration, and their suitability for exhibition purposes is well known, and largely taken advantage of. Towards autumn, and as the foliage begins to fade, the supply of water should be gradually lessened, until all the leaves die down; the pots should then be placed under the stage in the stove, where they can be looked to now and then, and a little water given if required. By no means allow the tubers to get dried up, as is often done; for, if so, they will frequently rot away inside; whereas, kept in a semi-moist condition, even the most delicate can be preserved. In this state, they may remain until the following season. Caladiums will not endure a very low temperature; from 55deg. to 60deg. is as low as they can be safely kept. Very few of those known as "true species" are grown, being superseded, for general decorative purposes, by the numerous hybrids which have been raised of late, principally from C. bicolor.

FIG. 313. CALADIUM CHANTINII.

C. argyrites (silvery).* l. small, sagittate, round colour light green; centre and margins white, with many irregular white blotches scattered over the remaining portion. Para, 1858. One of the smallest and most elegant of the genus, and much esteemed for table decoration. (I. H. 1858, 185.)

C. Baraquinii (Baraquin's). l. from 20in. to 30in. long; centre deep red; margin dark green. Para, 1858. (I. H. 1850, 257.)

C. bicolor (two-coloured).* fl., spadix shorter than the hooded spathe, which is contracted in the middle. June. l. peltate-cordate, sagittate, coloured in the disk. h. 1ft. Brazil, 1773. (B. M. 820.)

C. Cannartii (Cannart's). l. green, with pale blotches; veins deep red. Para, 1863.

C. Chantinii (Chantin's).* l. chiefly brilliant crimson, irregularly blotched with white, and margined with dark green. Para, 1858. See Fig. 313.

C. Devosianum (Devosie's).* l. angular, blotched white and pink. Para, 1862.

C. esculentum (edible). Synonymous with Colocasia esculenta.

C. Hardii (Hardy's). l. red-tinged, slightly spotted with white. Para, 1862.

C. Kochii (Koch's).* l. spotted with white. Para, 1862.

C. Lemaireanum (Lemaire's). l. green, with whitish venation. Brazil, 1861. (I. H. 1862, 311.)

C. Leopoldi (Prince Leopold's).* l. green, marbled with red, and blotched with pink. Para, 1864.

C. macrophyllum (large-leaved).* l. large, palish green, blotched with greenish-white. Para, 1862.

FIG. 314. CALADIUM MACULATUM.