Carnivorous Plants: Sundew

I am delighted to introduce you to the sundew (genus: Drosera)!  They live on every continent except Antarctica.   The genus Drosera is comprised of over ninety species!

The sundew grows sticky tenacles on its long leave blades as a way to catch insects. 

In many species, the leaf then folds over itself, like a sandwich, in order to preserve the insect’s nutrients from the rain and digest the insect more quickly.  This takes 24- 48 hours to occur. 

Folding leaf blade
Leaf blade just past ninety degrees
Leaf blade folding into a sandwich

The leaf blades may be long like grass blades, or they may be more circular, like baseball mitts, or oval, like spoons.

Notice this sundew has a stem that leads to a spoon-like shape. Only the spoon has tenacles.
Sundew shapes include spoons, grass-like blades, and rounded mitts.

What I love most about the sundew is that it glistens.

The clear droplets at the end of the tenacles shines in the sun like a drew drop.  These droplets are the plant’s mucilage, a glue-like substance.

The mucilage glistens

The sun makes the sundew look crystalline and gorgeous.

Henry Lyte*,  botanist squire of Lytes Cary Manor in Somerset, may have been the originator of the sundew’s English name.  In New Herbal of 1578, Lyte writes,

This herbe is of a very strange nature and marvelous: for although that the sonne do shine hoate, and long time thereon, yet you shall finde it always full of little droppes of water: and the hoater the sonne shineth upon this herbem so muche the moystier it is, and the more bedewed, and for that cause it was called Ros Solis in Latine, which is to say in Englishe, the Dewe of the Sonne, or Sonnedewe.

The sun glow on the sundew

Generally, the largest tenacles are at the edge of the leafblade.  These tenacles can only bend in one direction, but they are the tenacles that move most quickly, and so they are the ones that prevent the escape of large insects.  Tenacles get smaller as they move toward the inside of the leafblade. The inside ones can move in every direction. 

Notice the long tenacles below the leaf blade and the small ones above the leaf blade.

Tenacles are often red, although they may initially be green. In the cultivar below, the tenacles are clear because it is a special albino variety, likely Drosera capensis ‘Albino’.

Special albino variety

It is still not known what attracts insects to sundews.  There are no nectar glands, but the bright droplets of mucilage may themselves suggest nectar.

In New England, you can see wild sundews in the Great Swamp in Kingston, RI and in the Blue Hills Reservation in Massachussetts.

I wish you luck that you might discover these diamonds in a bog!


*This quote and the accompanying historical information is from the book Carnivorous Plants by Adrian Slack.

I learned about sundews from Carnivorous Plants by Adrian Slack.

I took these pictures at the Roger Williams Park Botanical Center.

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