Nepenthes

Nepenthes 

a genus of insectivorous plants of the family Nepenthaceae. They are terrestrial or epiphytic shrubs, sub-shrubs, or perennial herbs. The stems are generally prostrate or climbing and measure up to 6–20 m long; some forms are erect and short, reaching only 20–30 cm in height. The leaves are alternate and exstipulate. The unisexual flowers are usually four-parted and gathered in paniculate or racemose inflorescences. The fruit is a capsule. In mature leaves the midrib usually extends into a tendril that entwines itself around a support.

An ascidium that serves to capture insects develops at the end of the tendril. The ascidia are 5–15 cm long and 3–5 cm wide; in Nepenthes rajah, they are up to 25 cm long and 10–15 cm wide. The walls of the ascidia are often mottled with reddish spots. Insects are attracted by the nectar and the bright coloring of the ascidium; they slide down the smooth margin of the trap to the interior and drown in a fluid containing organic acids and digestive enzymes that are secreted by glandules at the bottom of the ascidium. These same glandules, after digesting the body of the insect, absorb the products of decomposition, thus compensating for the deficiency of nitrogen, phosphorus, and other substances characteristic of plants that usually inhabit swampy soils.

There are more than 70 species of Nepenthes, distributed primarily in the tropics of Asia. About 20 species are found on Kalimantan and Sumatra. A few species grow in Indochina, the Philippines, New Guinea, and tropical Australia. Many species and hybrids of Nepenthes are cultivated in greenhouses.

REFERENCE

Kholodnyi, N. G. “Charlz Darvin i sovremennye znaniia o nasekomoiadnykh rasteniiakh.” In C. Darwi Soch., vol. 7. Moscow-Leningrad, 1948.

S. S. MORSHCHIKHINA