Euphorbia nutans, a North American herb with distinctive oblong leaves that fold up at night, and its milky sap can irritate the skin

Euphorbia nutans, commonly known as Nodding Spurge or Eyebane, is a distinctive annual herb belonging to the Euphorbiaceae family. It's native to North America but has naturalized in various parts of the world, including Europe and Asia.

One of its most striking features is its unique leaf morphology. The leaves are arranged oppositely along the stem, presenting an oblong to oval-oblong shape. They typically measure between 1/3 to 1 1/3 inches in length and are about a third as wide. The leaf tips are either blunt or rounded, and they are mostly stalkless or have very short stalks. A notable characteristic is the asymmetrical leaf base, often exhibiting a shallow but distinct lobe on one side.

The leaf surface is not smooth; young leaves are covered in fine, curled hairs, which tend to disappear as the leaves mature. The lower leaf surface is usually light green, while the upper surface can sometimes display a reddish patch in the middle. The leaf margins exhibit variation in toothiness, ranging from coarsely serrated all around to only toothed at the tip or on one side, or even completely toothless.

An interesting behavior of Euphorbia nutans is the tendency of its leaves to fold up late in the day, a characteristic that has earned it the nickname "Eyebane." This phenomenon, known as nyctinasty, is believed to be a mechanism to conserve water and protect the plant from cold temperatures.

It's important to note that all parts of Euphorbia nutans contain a milky sap that can irritate the skin and eyes. Therefore, it's advisable to handle the plant with caution and avoid direct contact with the sap.

Ref.:

• https://gemini.google.com/