Euphorbia hirta

Native to tropical and subtropical America, this small annual herb has prostrate to ascending branches covered with conspicuous hairs. Paired leaves have finely toothed margins and may carry purple blotches. Dense, button-like clusters of tiny flower structures develop near the stems. Each contains separate male and female flowers surrounded by small white or pink appendages. The fruits are small, three-lobed capsules. Its milky sap irritates skin and eyes, and the plant is harmful if eaten. Photographed in Colombia.