Nepenthes - Carnivorous plant
The Nepenthes are carnivorous plants that capture their prey through mechanisms ofASCIDES OR SIMILAR deriving from the modification of some leaves.
The flap of the modified leaves loses, in whole or in part, its shape to become a trap that takes on the function of capturing small animal prey.
The preys are attracted in various ways (with colors, with nectar, etc.) and remain trapped in the ascidian. At that point, devices are activated to dissolve them and absorb the elements that derive from them.
Generally, the Ascids are filled with water and the device that determines the death and decomposition of the prey is of secondary importance (a typical example is the Sarracenia and the Darlingtonia) as very often both the death and the decomposition of the prey occur in the work of the bacterial microflora normally present in these structures and not thanks to enzymes secreted by the plant but due to the secretion of acids by the acid-resistent bacteria they contain.
In typical carnivorous plants there is no symbiosis with bacteria and the digestion of the prey, which is always extracellular, occurs thanks to the secretion of animal proteolytic enzymes (pepsins, trypsins) associated mostly with the secretion of acids (formic acid) .
In some carnivorous plants the secretion of acids and enzymes is continuous while in others the secretion occurs only under the stimulus of the presence of the prey.
The Nepenthes (family Nepentaceae) are original of the equatorial forests of Madagascar, Indus Malaysia, and Australia to which sixty species with very particular colors and shapes belong.
In this case the ascidium is in the shape of a jug and hangs from each leaf. These plants therefore have normal leaves that have a sort of hanging glass at their ends.
They are plants that can reach considerable sizes with ascidia that can have a capacity of up to two liters and in nature they are often epiphytes, that is to say that they have only aerial roots and grow attached to trees or on plant debris that they use as a support. from a sugary substance, we lean on the ascidium and slide on the internal walls of the ascidium ending up inside it where there are glands that produce special enzymes for the digestion of the prey.
As regards the Most common SPECIES there are about 80 that are divided into two large groups:
- lowland: lowland species that grow in warm temperatures and in very humid environments both day and night
- highland: it is the nepenthes that grow at high altitudes. Their place of origin is the Asian mountains and the climatic conditions are hot during the day and cold at night, therefore with strong changes in temperature and high environmental humidity.
Generally the plants that we find in specialized shops belong to the Iowland group as they are easier to grow in our apartments or in our climates.
The most widespread species is the Nepenthes ventrum which is a hybrid obtained by crossing the N. ventricosa is Winged N.; the hybrid obtained from the cross between Max. No x Mixta with very colorful and large ascidia.
As for the CULTIVATION of these carnivorous plants, relatively to the most widespread species (belonging to the lowland group), we can say that they are not difficult to cultivate. The Nepenthes belonging to the highland group present several cultivation problems as it is very difficult to reproduce their natural conditions and moreover they are almost impossible to find.
There Nepenthes it is a plant that can also be grown outdoors during the summer but during the winter it is advisable to bring it back indoors as, being a tropical plant, it does not adapt well to too low temperatures. In fact, the temperature margins within which these plants grow well are between 15-25 ° C.
First of all it must be said that they require small pots as their root system is extremely reduced, using a soil composed of peat mixed with delbarke and a small percentage of perlite.
Exposure must be in direct sunlight while trying to avoid the hottest hours of summer days.
Watering must be abundant and it is essential to use either demineralized or rain water as calcareous water is not welcome.
Another important aspect is the ambient humidity which must be high with frequent spraying, carried out in the morning, so that the plant is dry in the evening.
It multiplies by dividing the plant.