How to tell Caesar's mushroom from Jewelled amanita

The cap is 8–20 cm, hemispherical when young, then opening out to plano-convex. It's bright orange-red, darker in the centre and paler toward the edges. The surface is smooth and shiny, with no veil flakes (unlike the fly agaric), and the skin peels easily. The margin has clear radial striations, very pronounced in mature caps.

The cap is 4 to 10 cm across, occasionally up to 12 cm. It starts convex, almost bell-shaped, then opens out flat, sometimes with a slight dip in the middle.

The colour runs from pale straw to bright egg-yolk yellow, usually darker and more ochre in the centre, and older caps fade to cream. The surface is slightly sticky in wet weather. Flat white flakes, the remains of the universal veil, sit on top, thickest in the centre. They come off easily and rain washes them away, so a cap can be completely smooth. The margin of a mature cap is grooved, with short lines like the teeth of a comb.

The gills are free, crowded and golden yellow, one of the key features of the species (most amanitas have white gills). Spore print white or pale cream.

The gills are free or only just touch the stem, crowded, soft and white, and may turn slightly yellowish in old specimens.

The spore print is white. The spores are smooth and broadly ellipsoid, roughly 8–11 × 6.5–8.5 µm, but that only shows under a microscope.

The stem is 8–15 cm tall and 1–2.5 cm thick, cylindrical, widening slightly toward the base. It's bright yellow, smooth or finely scaly. Near the top hangs a broad, membranous yellow ring that droops like a skirt, and at the base is a large, white, free, sack-shaped volva, an essential diagnostic feature.

The stem is slender, 5 to 12 cm long and 0.5 to 1.5 cm thick, white or pale yellowish, smooth or finely downy, and fragile.

The ring is thin and membranous, like a little skirt, and sits halfway down the stem or lower. It doesn't last: often all that's left is a faint mark, and old specimens may have no ring at all. So a missing ring doesn't mean it isn't an amanita.

At the bottom the stem has a small rounded bulb. The volva hugs it tightly and ends in a narrow free collar at the top, sometimes broken into one or two rings or flakes. It isn't a tall sack as in the grisettes, nor a large, abruptly cut-off bulb as in the false death cap. The bulb is often sunk in the soil, so the mushroom needs to be dug up.

The flesh is white or slightly yellowish under the cap skin, firm, and doesn't change colour when cut. In the stem it's fibrous and solid, with no hollows.

The flesh is white, sometimes slightly yellowish in the stem, thin, and doesn't change colour when cut.

The smell is pleasant, mushroomy and faintly sweet. The taste is mild and nutty, which is exactly why the mushroom is so prized.

The smell is faint, hardly noticeable. Some authors mention a slight radish note, but most field guides say there's no distinctive smell. The only lookalike you can tell by smell is the false death cap, which smells of raw potato.