Nepenthes Rafflesiana trap structure - Essay Example

Keywords: Nepenthes Rafflesiana, Pitcher trap Nepenthes Rafflesiana of genus Nepenthes which belong to the family of Nepenthaceae are one of the most famous carnivorous plants having pitcher traps (Slack & Gate, 2000). Nepenthes have a total of more than 100 species with the bulk of species populated along the islands of Borneo and Sumatra (Bonhomme et al., 2011). Nepenthes pitcher plants including Nepenthes Rafflesiana have also developed specific adaptations like all other carnivorous plants due to lack of nutrients.

This nutrient deficiency is a result of the habitat in which these plants grow and they are mostly dependant on insect derived nitrogen (Gaume, Gorb & Rowe, 2002). As a result Nepenthes have these pitcher traps in order to catch and trap insects and then getting the nourishment by digestion and absorption. The structural architecture of the traps of Nepenthes Rafflesiana varies according to the geometry and surface features (Gaume et al., 2002). The pitcher trap is generally composed of three distinct parts (Gaume & Di Giusto, 2009).

The three parts named as peristome, waxy zone and digestive zone are all involved in their respective functions of attention, capture and digestion. A lid known as operculum is present above the peristome. The lid prevents the rain water from accumulating inside the pitcher and thus helps to prevent nutrient loss. According to Di Guisto et al. (2010) Nepenthes Rafflesiana show heteroblastic development defined by pitcher dimorphism according to their growth and maturity. Terrestrial pitchers or lower pitchers are linked to the young species whereas the aerial or upper pitchers are associated with the mature and climbing life forms.

The two pitchers thus also show different characteristics. While the aerial pitchers are elongated, shaped like a trumpet and greenish yellow in colour the terrestrial pitchers are more winged shaped, globular and reddish green in colour. Aerial pitchers have an approximate length of 3-12 inches while terrestrial pitchers are around 3-10 inches long. The pitcher traps mostly develop during summer. Although most leaves have a trap it is not a necessity that a leave must have a pitcher trap. Often due to lack of light, low humidity or difficulties in cultivation might cause a leaf to not develop a pitcher trap.

The initial sign of pitcher formation is a swelling on the tendril of a recently formed leaf. Leading towards maturity this minute swelling becomes filled with air and the first sign of colouring appears on it. A few days after the variegation appears, the lid of the pitcher opens and they become operational. In a week time the walls of the pitcher strengthen and they finally become completely mature. The pitcher trap consists of a mouth and a body. A hard, glistening and rounded collar or rim makes up the mouth of the trap (Bauer and Federle, 2009).

This rim is frequently furrowed with very apparent and obvious parallel ribs. Each and every rib ends inside the mouth in a very sharp downward direction. The angles created due to this downward pointing, house single nectar secreting glands between them. The body of these traps also varies from pitcher to pitcher. The body is more or less like a cylinder with a rounded base. The lower half of the body is often more bell shaped than the rest of