ACS Distance Education UK
Carnivorous plants are fascinating plants to grow at home; whether as a single novelty to amuze the children, or a large collection -as a hobby or to feed your passion for these botanical wonders.
Most carnivores are small but some can be a meter or more tall. They occur in all parts of the world from the arctic to tropics; and whilst thought of as wetland plants, some tolerate drier conditions than you might think.
Sundew species are spread widely in both temperate and tropical climates, in both the northern and southern hemispheres.
Appearance: Size and appearance is variable. Leaves can be as small as 1.5mm long, and as large as 60cm. Leaf shapes can be broad or narrow, simple or divided, occurring as a rosette hugging the ground surface, or on a climbing stem. Stems or leaves may emerge from a tuber or from roots that can be either fibrous, or fleshy.
The upper leaf surface is covered with masses of pin-like stalks (also called tentacles) each topped with a drop of sticky mucilage that glistens like dew drops in the light. Insects and other small animals can become trapped on one or two of these drops. As they struggle, they adhere to more and more, being held more firmly to the plant. The longest tentacles tend to occur along the leaf margins; and these are able to change direction relatively quickly to help trap the prey.
Glands located at the ends of the tentacles are capable of excreting not only the sticky mucilage, but both enzymes and a weak acid which together can digest the animal tissues.
Culture: Most grow well between 15 and 35 degrees Celsius; and some at lower temperatures.
Health: Mucilage production is essential for plants to catch insects, which in turn is essential for it to obtain proper nutrition. A lack of mucilage can be caused by inappropriate light, temperature, humidity or air movement.
Insects can occasionally be a problem, despite the fact that it eats insects. Aphids, for instance may occasionally feed off the crown and this may lead to deformed growth. Root rots can cause sundew plants to wilt. Physical problems can also affect health, including soil compaction and heat stress. Humic acid, dust or other substances may sometimes cover leaves, reducing the stickiness of mucilage and preventing a plant's ability to catch insects.