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Cobra's Head Re-examined

A Darlingtonia's pitcher dome is scattered with numerous white patches, called fenestrations.

Looking at the cobra plant's pitcher from the side, you can draw a horizontal line, cutting through the lower portion of the cobra head. Above this line,  there are numerous hairs (1 mm long) covering the inner surface of the cobra dome.  Just like the hairs on the fishtail appendage, these hairs in the dome interior all point in the direction of the spiral pitfall in the pitcher.

Another note is that using this same imaginary line as a divider, the characteristics of the fenestrations changes drastically as shown below.  Above this line, the areoles are very translucent, almost transparent. Below the line, the translucency abruptly decreases, due to the change of surface texture of the areoles. This difference of the degree of fenestration transparency is undetectable if these fenestrations are observed from the pitcher exterior.  But as you enter the cobra dome interior, as the insect would, the areoles above this line are almost glass-like.  Below the line, the white patches are white windows, still providing enough light to brighten up the spiral pitfall, but not transparent. 

The upper areoles are more glass-like, compared with the lower areoles which look more cloudy due to the surface texture.

July 2007.

Tiny hairs (1 mm) grow on the ceiling of the dome.  The hairs also grow on the areoles.

Now,  going down the pitcher tube, right after the conduction zone, the tube interior is covered with thin hairs. These down-pointing hairs in the pitcher tube wall prevent the prey from scaling the wall.

Given the mature pitcher height of 50 cm, say, the lower 20 cm of the tube is lined with these fine hairs.
The picture below is the upper portion of this zone.

The fine hairs continue down to the bottom of the pitcher tube. These hairs do not intermesh. 

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