Wednesday, July 8, 2009

Sundew

Yesterday a parasitic plant, today a carnivorous plant, or more precisely an insectivorous one. I came across the round-leaved sundew while on a walk with a botanist and a dragonfly enthusiast. George, the botanist, spotted this diminutive sundew along with bog clubmoss growing in a small seep at the base of a disturbed hillside.

Round-leaved sundew (Drosera rotundifolia)

The sundew thrives in sunny, boggy areas. The basal rosette of roundish leaves lie flat to the ground. The top side of the leaves are covered with reddish hairs tipped with glands that secrete a sticky substance (resembling a dewdrop) that traps insects. When it catches an insect, the leaf blade folds inward around the prey. The fine inner hairs secrete enzymes that digest the insect. The nutrients that are released by this digestion are absorbed by the glands in the hair tips. After the meal is digested, the leaf unfurls, ready to trap another insect.

We came upon these sundew in late morning under a clear blue sky, so the photos were a little washed out. You can just make out a slender stem rising from the center of the basal rosette of leaves. This is the flower stalk which bears flowers on one side of the stalk. The sundew is very intolerant of shade. Even grasses, sedges, and ferns can shade it out. This exposed rocky slope is in full sun and has standing water at the base because of all the rains this summer. Sundew are capable of colonizing such disturbed sites, although over time as vegetation grows up, the sundew may disappear from this ephemeral habitat.

We soaked up the sun while peering down at the lovely sundews. It helps to wander along trails and woodland edges with a botanist and a dragonfly wizard. Their eyes are searching for and seeing different things; we had many unexpected finds on Monday.

No comments:

Post a Comment