Amanita gemmata, commonly known as the gemmed amanita or the jonquil amanita, is an agaric mushroom of the family Amanitaceae and genus Amanita. The fruit body has a cap that is a dull to golden shade of yellow, and typically 2.5–12 cm (1–4+3⁄4 in) in diameter. The cap surface is sticky when moist, and characterized by white warts, which are easily detached. It is initially convex, and flattens out when mature. The flesh is white and does not change colour when cut. The gills are white and closely spaced. The stem is pale yellow, and measures 4–12 cm (1+5⁄8–4+3⁄4 in) long by 0.5–1.9 cm (1⁄4–3⁄4 in) thick. The partial veil that covers the young fruit body turns into the ring on the stem at maturity. The spore print is white, while the spores are roughly elliptical, and measure 8–10 by 6.5–7.5 μm.

This species is a mycorrhizal fungus, widespread in Europe. It can grow either singly, scattered, or in groups. It prefers habitats like coniferous and mixed forests and alongside paths, where it fruits in summer and fall. It is a toxic mushroom, containing muscarine, also found in many species in the Clitocybe and Inocybe genera, as well as in Amanita muscaria and A. pantherina, albeit in insignificant quantities in the latter two. It is often confused with various other European species. A. gemmata resembles the false death cap, tawny grisette and panther cap mushrooms. Its cap is brighter in color than the former, and more yellow than the latter two.