This section is from the book "The Standard Cyclopedia Of Horticulture Vol2", by L. H. Bailey. See also: Western Garden Book: More than 8,000 Plants - The Right Plants for Your Climate - Tips from Western Garden Experts.
(Origin Of Name Obscure)
Araceae. Warmhouse large-leaved plants, grown for the foliage; also employed in summer bedding.
Herbaceous perennials, arising from large rhizomes or tubers, acaulescent, with usually beautifully marked, long-petioled leaves; the secondary nerves oblique to the few spreading primary nerves: peduncles usually solitary; spathe with the tube convolute, constricted at the throat, the blade boat-shaped; spadix erect, a little shorter than the spathe, the lower part naked, stipelike, the staminate part longer than the pistillate; flowers unisexual: fruit a berry, white. - A dozen or less species in tropical S. Amer. Two of the species are immensely variable, and many named horticultural varieties are in the trade. Engler in DC. Monog. Phan. 2:452 (1879); also F. S. 13.
As soon as Caladium plants begin to lose their leaves in the fall, water should gradually be withheld until the leaves are all gone. The pots should then be removed to a position under a bench, and laid on their sides, or taken from the soil and placed in sand. During the resting period they should not be subjected to a lower temperature than 60° F., and kept neither too wet nor too dry. About the beginning of March the tubers should be started for the earliest batch to be grown in pots. Arrange the tubers in their sizes, and keep each size by itself. The largest-sized tubers will start quickest, and it is desirable to begin with these for pot-plants. Start them in chopped moss in boxes. The tubers may be arranged rather close together in the box, and merely covered over with the moss to the depth of about an inch. The new roots are made from the top part of the tuber, so it is important that this part should be covered to encourage the roots. For starting, a heat varying between 70° and 85° will suffice. As soon as a healthy lot of roots makes its appearance, the plants should be potted, using as small-sized pots as possible. The soil for this potting should be principally leaf-mold, with a little sand.
In a short time they will need another shift; the soil .should on this occasion be a little stronger; give a position near the glass, and shade from strong sunshine. - New forms are raised from seed, this operation being an exceedingly easy one with the caladium, as they cross-fertilize very readily. The flowers, unlike those of the Anthurium, are monoecious, the females ripening first. To pollinate them, part of the spathe must be cut away. Seedlings at first have the foliage green, and it is not until the fifth or sixth leaf has been developed that they show their gaudy colorings. Propagation of the kinds is effected by dividing the old tubers, the cut surfaces of which should be well dusted with powdered charcoal to prevent decay. - As bedding plants, the fancy-leaved caladiums are gradually becoming more popular. To have them at their best for this purpose, the ground should be worked for some time previous to planting out, with a goodly quantity of bone meal incorporated with the soil. The tubers are best put out in a dormant state, as then they make very rapid progress, and eventually make finer plants than when they are first started in the greenhouse, as by this system they are too likely to sustain a check in the hardening-off process, and lose their leaves.
The fine, highly colored kinds are not so well suited for outdoor work as those having green predominating in the foliage, but some of the kinds, such as Dr. Lindley and Rosini, do remarkably well. Frequent watering with manure-water is absolutely necessary to the development of the foliage, both outdoors and in. (G. W. Oliver.)
Fig. 732. Caladium bicolor variety Chantinii. (No. 17).
It will be seen that most of the cultivated caladiums are considered to be forms of C. bicolor and C. pictura-tum. Only five species are concerned in the following list: Schomburgkii, 1; marmoratum, 7; bicolor, 8; pic-luratum, 48; Humboldtii, 57.
A. Blade not at all peltate, obliquely elliptical-ovate.
1. Schomburgkii, Schott. Petiole slender, 4 times longer than the blade, sheathed one-third its length; blade obliquely elliptical-ovate; midrib and 4-5 acutely ascending primary nerves silvery, pale, or red; sparsely spotted above, paler beneath. French Guiana to Para. -Runs into the following forms:
(1) Veins red.
2. variety marmoreum, Engl. Blade dull green, with brownish red nerves, bordered with yellow.
3. variety erythraeum, Engl. (C. Schmitzii, Lem. C. cordatum, Hort.). Midribs and nerves red. I.H. 8:297.
4. variety pictum, Engl. With white or red spots between the red veins. S. Amer.
(2) Veins silvery or green.
5. variety argyroneurum, Engl. (C. argyroneuron, C. Koch. C. Schoelleri, Lem.). Midrib and veins silvery. I.H. 8:297.
6. variety subrotundum, Engl. (C. subrotundum, Lem.). leaf - blade rounded at the base, or shortly cordate, with white or red spots. Brazil.
aa. Blade distinctly peltate.
B. leaf sagittate-oblong-ovate; basal lobes united for two-thirds their length, or more.
7. marmoratum, Mathieu (Alocasia Roezlii, Bull. C. thripedestum, Lem.). Petiole cylindrical, 12-16 in. long, twice as long as the blade, variegated; blade 6-8 in. long, 4-6 in. wide, dark green, with irregular gray, yellowish green and snow-white spots, glaucous-green beneath, sagittate-oblong-ovate, the upper lobe semi-ovate, slightly cuspidate, the basal ones unequal, one-third or one-half as long as the upper, connate two-thirds to three-fourths their length: spathe-blade pale green, 2-3 in. long. Ecuador. I.H. 5, p. 59, desc.
bb. leaf not as above; basal lobes united one-third their length or less.
c. Shape of If. ovate-triangular, or ovate-sagittate (8-47).
8. bicolor, Vent. (Arum bicolor, Ait.). Petiole smooth, 3-7 times as long as the blade, pruinose toward the apex; blade ovate-sagittate, or ovate-triangular, variegated above, glaucous beneath; upper lobe semi-ovate, narrowing gradually to a cuspidate point, the basal ones one-half to but little shorter than the upper, oblong-ovate, obtuse, connate one-fifth to one-third their length. S. Amer. introduced into cultivation in 1773. B.M. 820. - Very common in cultivation, furnishing many of the fancy-leaved caladiums. The marked varieties are as follows (9-47):