The tropical pitcher plant Nepenthes alata is a carnivorous plant endemic to the Philippines, and a natural dweller of the tropical rainforest. Like all other plants, it uses light to photosynthesize sugar, but because of shortage of nitrogen nutrients in the ground the plant complements its diet by trapping and digesting insects. The insects are attracted to the colour and fragrance of the pitcher-shaped traps, drown in the liquid inside, and are digested by special enzymes in this liquid. The traps develop at the tip of the midrib of the leaf, whose shape gives this plant its common name. The petiole of the leaf is broad, wing-like, from which the plant species’ scientific name is derived. The petiole is green and fulfils the role of photosynthesis usually fulfilled by the leaf blade in most other plants.

However, the pitcher plant is not only a predator of insects. It also needs them for pollination. Killing its pollinators would obviously be disadvantageous to the plant, so in order not to inadvertently trap the pollinators, a separation has evolved between the organs used for predation (pitcher) and for reproduction (flowers). The pitcher plant displays a spatial separation, as well as distinctive colour and odour differences between the flowers and the traps.

These plants are currently flowering in the Garden’s tropical greenhouse: the top photograph (previous page) presents the pitcher-like trap and the bottom one – the male inflorescence.

These types of species create many hybrids, both in nature and in cultivation, and some of those in our garden seem to be the result of a natural hybridization between N. alata and N. ventricosa, named Nepenthes X ventrata.

Photo: Moshe Peri

Photo: Moshe Peri