CALLOSE. Callous, hardened.
CALLOUSLY-GLANDULAR. Having hardened glands.
CALLOUSLY-SERRATED. Having hardened serratures.
CALLUNA (from kalluno, to sweep, from the use of the plant in brooms). Common Ling; Heather. ORD. Ericaceæ. A small hardy spreading shrub, very common throughout Northern and Central Europe. Corolla campanulate, four-lobed, shorter than the calyx. For culture, see Erica.
C. vulgaris (common).* fl. disposed in long, terminal, spicate racemes. July to September. l. trigonal, obtuse, very short, imbricating in four rows, having the margins revolute and the base sagittate. h. 1ft. to 3ft. Britain. There are numerous very ornamental varieties of this species, which are admirably adapted for planting in borders and clumps. The white-flowered (alba, Serlii, and Hammondi), flesh-coloured (carnea), and double-flowered varieties (fl.-pl.) are all well worth growing in shrubberies; aurea and argentea, with gold and silver coloured shoots, are also very ornamental. The value of the common form can scarcely be over-estimated for planting on barren hill sides or spaces; it affords excellent shelter for game, and food for bees.
CALLUS. The new formation at the end of a cutting before it puts forth roots; when the Callus is formed, it shows that the cutting is in a healthy state.
CALOCHILUS (from kalos, beautiful, and cheilos, a lip; referring to the beauty of the labellum or lip). ORD. Orchideæ. Interesting greenhouse terrestrial tuberous-rooted orchids, allied to Epipactis. Sepals yellowish-green; lip purple, covered with rich brown hairs. For culture, see [Bletia.]
C. campestris (field). fl. greenish and brown. April to June. l. narrow, oblong, pointed. Stem leafy, slender, terete. h. 9in. Australia, 1824. (B. M. 3187.)
C. paludosus (marsh).* fl. very similar in colour to those of C. campestris, but rather larger. May and June. l. rather broader. h. 9in. Australia, 1823. (F. A. O., part 4.)
CALOCHORTUS (from kalos, beautiful, and chortos, grass; referring to the leaves). Mariposa Lily. ORD. Liliaceæ. Handsome bulbous plants. Flowers showy, on erect scapes; perianth deciduous; three outer segments sepaloid, three inner ones much larger and broader, and bearded on the inside. Leaves ensiform. Bulbs tunicated. These have not, hitherto, been generally grown in the open air with much success; but in warm localities and sheltered positions, they may be flowered outside. A frame, in a sunny situation, is the best possible place for their cultivation. Here they may be fully exposed to the sun and air, during mild weather, through the winter; and, when expedient, they may be protected from excessive moisture, as that is the primary cause of failure, rather than cold, for they are perfectly hardy, and capable of enduring all the frost we are likely to get. From May onwards, the lights might be wholly removed. From the end of June to August, the bulbs will be in bloom, when, if necessary, the flowers should be fertilised to secure seed; and when the capsules are forming, material assistance would be given by placing the lights on again, allowing plenty of air. Assuming that fresh bulbs are being planted, they should be in the soil early in the autumn, as nothing is more prejudicial than keeping them dry through the winter. A good depth of soil should be provided, composed of fibrous loam, leaf soil, and sand, in equal proportions, in a well-drained position. The bulbs must be planted 3in. deep, and some sand placed about them; they may be left undisturbed for years. Of course, where no frame can be provided, they may be planted in a well-drained, sunny position in the same soil. They are also easily managed in pots, but it is necessary to pot in the autumn, and keep in a frame. Through the winter, they must never be allowed to get dry, until the leaves are withering in the autumn, when water may be withheld.
Propagation. This may be effected by seeds or offsets, and by the tiny bulbs frequently produced on the upper portion of the stem. Sow seeds in pans, in a cool house or frame, as soon as ripe, or in the early part of the year, and keep the plants close to the glass during their early stages, as they are very liable to damp off. Sow thinly, so as to enable the young plants to pass a second season in the seed pots or pans. Early in the third season, pot off and plant out singly, encouraging them to grow freely. Propagation by offsets is the most usual method. With liberal treatment, most of the species increase pretty freely. The offsets are best removed when the plants are in a dormant state. They may be either grown in pots or pans, or planted out in pits or frames, until they reach flowering size. During the season of rest, it is the safest plan, with those in pots, to keep them in the earth in which they were grown.