Stemodia durantifolia is a species of flowering plant in the plantain family known by the common names whitewoolly twintip and purple stemodia. It is native to parts of the Americas, including Mexico and the deserts of California and Arizona. It grows in riparian habitat. It is a perennial herb producing a hairy, glandular, erect stem 10 to 50 centimeters tall. The toothed lance-shaped leaves are found in pairs or triplets at stem nodes, their bases often clasping the stem. The inflorescence is a raceme of violet flowers, each centimeter-long corolla held in a calyx of hairy, pointed sepals. The plant can be seen in bloom throughout most of the year.