The inner surface of the pitcher is divided into four zones based on the function and structure of the surface. These four general zones are common to all species of Sarracenia. The first zone encompasses the area on the undersurface of the hood. It is called the attractive zone and contains the nectar glands intermingled with stiff, downward pointing hairs which direct the insect's movement toward the bottom of the pitcher. Zone 2, containing numerous nectar-producing glands, is smooth and is located just below zone 1. The digestive glands are located in the smooth waxy walls of zone 3. While the first two zones offer a precarious foothold for the insect, zone 3 offers none. Moving downward in the pitcher, zone 4 is distinguished from zone 3 by the appearance of downward pointing hairs. This is the digestive and absorptive area. The digestive enzymes and bacteria in the fluid in this region of the pitcher are responsible for digestion of prey. The function of the downward pointing hairs in this zone is to prevent prey from leaving the fluid. Indigestable insect remains are often found as a blackened mass in this region at the end of summer. (Fig. 3-2)
Presumably, luring of prey is accomplished by secretion of nectar, coloration, odor, and fenestrations of the leaves. (Photo 3-2) Although not all of these enticements are
Was this article helpful?