Label the Parts of a Venus Fly Trap

All 5 parts on the diagram

Show the list

Lobe One of the two halves of the trap. They close like a book.
Midrib The rib down the middle. The two lobes hinge on it.
Teeth (cilia) Stiff bristles along the edge. They lock together when the trap shuts.
Trigger hairs Three stand on each lobe. Touching them sets off the trap.
Digestive glands Tiny glands on the inner face. They digest the insect and take in the food.

How this list was compiled: Every name checked on 2026-10-03 and kept only where two of these use it. (1) Charles Darwin, Insectivorous Plants, 1875, chapter XIII, Dionaea muscipula (public domain), https://www.gutenberg.org/ebooks/5765 : the roots are small, springing from a bulbous enlargement; the bilobed leaf with its foliaceous footstalk; three minute pointed filaments on the upper surface of each lobe, extremely sensitive to a touch; the margins prolonged into sharp rigid spikes that inter-lock like the teeth of a rat-trap; the midrib strongly developed; the upper surface thickly covered, except toward the margins, with minute glands that secrete and absorb. (2) Flora of North America vol. 6, Dionaea, read at efloras.org, http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=110284 : scapes from bulblike rhizomes wrapped in fleshy petiole bases; roots adventitious, white, unbranched; petiole winged; blade of 2 hinged lobes, margins stoutly bristled, hinged along the midrib, with 3 trigger hairs on each upper surface; petals white. (3) North Carolina State Extension Gardener Plant Toolbox, Dionaea muscipula, https://plants.ces.ncsu.edu/plants/dionaea-muscipula/ : native to coastal North Carolina and a small area of South Carolina; a low basal rosette of leaves; the trap at the end of each leaf, folded in 2 hinged lobes, the edges bristly; six tactile hairs, any two of which shut the trap; digestive enzymes; white flowers atop a leafless stalk (scape), each with 5 petals. (4) Wikipedia, text only, Venus flytrap, https://en.wikipedia.org/wiki/Venus_flytrap : a rosette of leaves from a short bulb-like subterranean stem; a flat petiole and two terminal lobes hinged at the midrib, which form the trap; three trigger hairs on each lobe; two touches in quick succession close the trap; the edges fringed by cilia that mesh together; digestive glands inside the trap; a flower atop a long stem. (5) F. E. Lloyd, The Carnivorous Plants, 1942, chapter XII, Dionaea, full text read, https://archive.org/details/dli.ernet.206006 : a rosette of leaves arising from a rootstock; in the seedling there arises at once a rhizome bearing small leaves; long scapes with white petals; the leaf a basal footstalk and a blade which is a trap; two lobes united along the middle line by a thick midrib; the outer margins ciliated, with a row of coarse projections, prongs or teeth; the cilia intercross to form a barred cage; six slender sensitive hairs, the trigger hairs; the digestive glands. Rhizome stands on (2) and (5), and cilia on (4) and (5); Darwin and Wikipedia call the same stem a bulbous enlargement and a bulb-like object. Licence: own work

The drawing: Drawn for this site on 2026-10-03 from plain geometry; own work, nothing traced. Licence: own work

How it works

To label the parts of a Venus fly trap, name the five numbers on one open trap, seen face-on: one of its two halves, the rib between them, the spikes on the edge, and two things on the inner faces.

Read the full guide

Venus fly trap word bank

In alphabetical order, to copy onto the board: digestive glands, lobe, midrib, teeth (cilia), trigger hairs.

Teeth, trigger hairs or glands

All three are small and sit on the lobes. The teeth (3) are the stiff spikes all along the outer edge. The trigger hairs (4) are the six thin bristles that stand up from the inner faces, three on each lobe. The digestive glands (5) are the many small dots. A lobe (1) is one of the two broad halves, and the midrib (2) is the thick rib they hinge on.

When marking, take hinge on line 2, cilia or bristles on line 3, and sensitive hairs on line 4.
The trigger hairs and the glands are drawn far larger than life, so they can be found.
Six more names, from the leaf stalk down to the roots, are on the whole plant of the labeled diagram.

Questions and answers

What color is a Venus flytrap?

Green, often with red on the inner faces of the lobes, which hold a red pigment. Some garden varieties have deep red or yellow traps.

Where do Venus flytraps grow in the wild?

They are native to wetlands in North Carolina and South Carolina, on the United States East Coast.

What does a Venus flytrap eat?

Chiefly insects and arachnids, such as spiders. Each one is caught in a trap, which is the end part of a leaf.

How fast does a Venus flytrap close?

In roughly a tenth of a second. It shuts once two trigger hairs are touched within about twenty seconds of each other, or one hair is touched twice quickly.

How long does a Venus flytrap take to digest an insect?

About ten days. By then the insect is reduced to a husk, and the trap opens again, ready for reuse.