nepenthes rafflesiana upper pitchers are funnel-d and often bear a distinctive raised section at the front of the peristome.

carnivorous plant nepenthes upper pitcher trap insectivorous modified leaf unique structure rainwater collection slippery surface downward-pointing hairs prey capture digestive fluid nutrient absorption adaptation carnivory plant anatomy specialized organ insect trapping morphology enzymes biomimicry biodiversity survival strategy nutrient-poor environments evolution rainforest harvesting predator-prey relationship botanical feature nectar digestion predator avoidance pitcher shape symbiotic relationships interactions ecological niche charles darwin fascinating flora leaf aquatic habitat scientific study habitat diversity role tropical plants natural selection predatory mechanism rainforest behavior