Diversity of Caladiums-An Ornamental Aroid in Goa

Caladiums are ornamental aroids which serve as a vibrant and colourful option for our landscape, especially shady landscape. They come in a wide variety of colours and foliage patterns and are grown primarily for their long lasting bright colourful foliage. They will provide an immediate appeal and colour in the landscape. Caladiums have variegated and multi-coloured foliage which can be showcased as a single specimen or grouped for spectacular impact. They are inconspicuous flower bearing and coloured ornamental plants which will thrive bright either on the ground or in containers placed in shady locations around the landscape.

Caladiums are a genus of plants of the family Araceae. They belong to the Kingdom Plantae, Division Magnoliophyta, Class Liliopsida, Order Alismatales, Family Araceae and Genus Caladium. Caladiums originated in the tropical or subtropical region of Central America and South America. Modern cultivars are primarily derived from Caladium bicolour and its hybrids with other caladium species. They are grouped under the name Caladium hortulanum. Caladiums are tropical plants grown from tubers.

A caladium plant is comprised of tubers, stalks and the most important showy part, the leaves. The leaves themselves are the most colourful part of this plant. These plants are commonly grown for their dramatic multicoloured foliage. Caladium leaves are shaped like hearts, arrows, straps or lances in various colour combinations and with wonderful patterns. The brilliant foliage of this classic plant light up your garden and brightens the shady spot. The variety of sizes, tints and shapes of leaves in caladiums inspires the creative gardener to have unique colour in
shady landscape until winter.

Commercial Caladium cultivars possess very diverse leaf shapes. There are three forms in caladiums that are most widely cultivated and are broadly classified as fancy, lance and strap. The first and the most common type of caladiums is referred to as “Fancy Leaf”. This is the more commonly seen and the traditional caladium in cultivation. They have heart-shaped leaves (triangular, round or ovate) with three main veins on each leaf arranged in the form of an inverted letter “Y”, a peltate petiole attachment, and the two basal lobes are joined for more than one-fifth of their length and separated by a short narrow sinus.

This type of caladium typically grows about knee high and has an average leaf size comparable to a dinner plate. The second group of caladiums is referred to as “Strap & Dwarf”. They have narrow linear or ribbon-like leaves, one main vein and no obvious basal lobes. They have smaller leaves, comparable to a salad plate. Heights for these types of caladiums can vary from ankle high to almost knee high. The 6-inch to 12- inch, leaves emerge from the ground on arching stems that are generally 1 foot to 2 feet tall.

The third type of caladium is referred to as “Lance”. Lance-leaved types are intermediate between fancy and strap types. Leaf blades are broad sagittate to cordate-lanceolate, with basal lobes not obvious or broadly separated by a sinus. Generally, strap or lance left caladiums are much shorter in plant height, produce a number of leaves, more sun tolerant and produce smaller tubers than fancy leaved plants.

Most Caladiums in cultivation grow to about 60 cm high and 60 cm wide, although dwarf varieties are now in cultivation. The shape of caladium leaves directly affect the acceptance of the same in marketing. Larger, fancy-leaf types (heart-shaped leaves) are best suited for a perfect show of colour. Strap-leaf types (shorter plants with bunches of leaves) or dwarf types (smaller, heart-shaped leaves) is best suited for pots and window boxes. All of these caladium types can make a dramatic statement in the landscape.

Most caladiums are asexually propagated by division of tubers or from tuber pieces (chips). Leaf colour is another important characteristic of caladium which determines its ornamental significance. Leaf colours in many caladium cultivars are extremely diverse and fascinating. It is determined by the colour of the veins (main, secondary and peripheral), interveinal areas, spots and /or blotches. Leaf colour variation is primarily caused by changes in anthocyanin distribution in the foliage.

Chlorophyll content also affects the leaf colour variation. The colour variation in caladiums often occurs as spots, streaks, or blotches. The foliage of caladiums may be splashed with combinations of red, pink, rose, white, burgundy chartreuse, and green – often with several colours combined. In caladiums, leaf colours and coloured areas can be quite variable on the same plant with changes in plant development or environmental conditions. Leaf colour pattern often changes from initial to later leaves in caladium.

However, the main vein colour of the leaf is an exception and is rather stable under dissimilar environments on different plants, or even at different stages of development. This remarkable stability of colour expression in main veins of leaves has been very useful for cultivar description and identification in Caladiums.

Most of the caladiums prefer filtered sunlight and shade. A shady area with moist, well-drained soil that is rich in organic matter should be selected for caladium planting. They should be watered regularly. The soil should be kept slightly moist. Mulching is effective which help retain soil moisture and conserve water. Caladiums are tuber – rooted and can be easily propagated by transplanting a piece of the tuber with the eye. Caladiums are remarkably free from major insect or disease problems and thrive in hot, humid weather. They grow best in shade to partial shade (two hours to four hours of direct sun, preferably morning sun).

Caladiums can be grown in containers or pots to accent shady spots or can be clumped together within beds and borders or can be used as indoor house plants. The bright leaves of caladiums, with their bold texture, embellish our shady gardens from May until October, after which the tubers go dormant. In late September or October, caladiums go dormant with cooler temperatures. When grown with poor management, particularly in areas of deep and heavy shade, the plants will produce small and weak tubers. The performance of such a crop may not be good, whether they are left in the ground or dug and stored.

Under the right circumstances and with proper management and care, the tubers planted in summer can be dug in the winter and planted next April or left in the ground to provide a beautiful display again next year – and for years to come.

Description of selected Caladium cultivars (For details click on the link given below)

Source-

• Central Coastal Agricultural Research Institute, Ela, Old Goa, Goa