Cacti & Other Succulents
A layman can not distinguish between a cactus and other succulents. The common belief is that the drought resistant plants, which have no leaves, are cacti and the leafy ones are succulents. First let us find out the meaning of the words ‘Cacti’ and ‘Succulents’. The term ‘succulent’ is used for any plant – irrespective of its family – which has ability to sustain in drought conditions. Succulent plants store available water in roots/stems/leaves. This stored water sees them through drought period. So, the term ‘succulent’ describes just the property of plants. Different succulent plants belong to different families. Cactus too is a succulent as it stores water in its body. Now one may ask a question, “If cati too are succulent, why are they segregated from other succulents?” The answer to it is “Cactus” is a name of a family of succulent plants. So only those plants which belong to this family can be called as ‘cactus’. Each and every species of the cactus family is a succulent. However, this in not the case with other families. For instance, Aloe, Gasteria, Haworthia and Yucca are succulents belonging to Lily family. But Dracaena, Asparagus, Tulip, Spider plant, Tiger Lily and Onion belonging to the same family are not succulents. In Euphorbia family Croton, Castor, Amla, Acalypha, Poinsettia are normal plants. But Pedilanthus, some Jatropha species and Euphorbia nerifolia etc. are succulent.
A cactus can be easily identified by the areole. Areole is a wooly pad under the spines of a cactus. Irrespective of the species of cactus, areoles are found on all cacti plants. The spines are really modified leaves. The leaves lose moisture through their pores in the process of transpiration. So to conserve the water, leaves in most cactus plants have modified to spines. Certain cacti do have normal leaves. Pereskia grandifolia (rose cactus) and Pereskia godseffian (lemon creeper) have normal leaves. Many opuntia Cacti (Pad cactus) do have scaly leaves on their new growth. These scaly leaves drop down soon. Some cacti are without spines. Epiphyllum (¥ÉÀEò¨É³ý ), Zygocactus (Christmas cactus), Schlumbergera and some species of Astrophytum do not have any spines. But these plants do have areoles. Contrary to belief, some cacti and succulents can not tolerate harsh sunlight. Such succulents in nature grow in semi-desert areas or grow in the rock crevices or under the shelter of larger plants. Cacti may be globular, cylindrical or pad shaped.
Euphorbia succulents have superficial resemblance to cati. But Euphorbias have no areoles. All Euphorbia succulents have milky sap. Many Euporbia succulents produce leaves in the growing season. In lean periods these leaves drop down to conserve water; but, in some species, leaves will continue to grow on the plant all year round.
Stapelia, Huernia, Caralluma too superficially look like to cactus. But these plants belong to Asclepia family. Some stapelia plants have peculiar coloured flowers, but most of these emit foul smell. This is to attract carrion flies; who pollinate these flowers in nature.
Though succulent plants can sustain long periods of drought, they flourish well only when given adequate water. The succulents having leaves need more water compared to the ones who have no leaves. Soil used for all succulents should be sandy. Sandy soil drains out water fast. One thing the succulent plants do not like is stagnation of water. In fact it is always safer to feed them less water than over water them. Watering should be done only after topsoil looks quite dry. These plants should be watered well before sunset, else, water droplets remaining on the hairy plants can cause fungus rot. Over watering will make most succulents to turn to pulp. Some varieties of Euphorbia and cacti do tolerate a lot of water. Such succulents are often planted as hedge plants.
Propagation : Some cactus plants produce fruits which have seeds. Cacti can be grown from seeds. Cactus plants also can be propagated with stem cuttings and by gafting. Cereus pentagonus, Nyctocereus, Hylocereus and pereskiopsis are cactus plants very suitable as grafting stock.
Sedum, Echeveria, Kalanchoe can be propagated from leaves. Gasteria and Sansevieria can be propagated even with pieces of leaves.
Some succulents have a tendency to deformities. The deformed varieties, due to their peculiar shapes and rarity are costlier. These deformities are of two types – ‘monstrous’ and ‘cristate’. A monstrous plants suddenly grow multiple growing heads. When a plant starts growing like a crest of a cock (fan shaped) it is called as cristate growth. As normal plants occasionally turn to monstrous or cristate, some deformed plants grow certain shoots, which are normal.
Aquatic Plants : Water lilies, Nymphoides, water Hycinth, Pistia, Salvinia and Duck weeds can be grown in old bath tubs, kitchen sinks, aquarium tanks or tubs. Pistia, Salvinia, Duck weeds and Nymphoides can be grown in small plastic basins. Though all these plants are aquatic, they need soil, laid at the bottom of the container. Soil provides nutrients for their healthy growth. Roots of some aquatic plants do anchor and grow in the submerged soil. All these plants need at least 2 hours of direct sunlight. Guppy fish kept along with these aquatic plants will eradicate mosquito larvae, which otherwise grow in stagnant water.