Field Mushroom vs Wine Cap
Agaricus campestris compared with Stropharia rugosoannulata — how to tell them apart in the field.
How to Tell Them Apart
Some Agaricus species have similar cap shapes and dark spore prints. Distinguished by the chocolate-brown (not purple-black) spore print, pink to brown gills (not lilac-gray), and lack of the distinctive cogwheel ring. Agaricus species also tend to have a more distinctly mushroomy or anise-like odor.
Side-by-Side Identification
| Trait | Field Mushroom | Wine Cap |
|---|---|---|
| Cap | 3–10 cm across. Starts as a smooth white dome, opens to a broad convex shape, sometimes flattening with age. Surface is dry, white to cream, occasionally developing fine brownish scales in the center. Feels silky when young. | 5-20 cm across (occasionally larger). Convex, expanding to broadly convex or flat. Deep wine-red to burgundy when young, fading to reddish-brown, tan, or straw-colored with age. Surface is smooth, slightly viscid when wet. Flesh is white, thick, and firm. |
| Gills | The key ID feature. Start bright pink in young specimens, darken to chocolate brown, then near-black as spores mature. Closely spaced, free (not attached to the stem). NEVER white — if they're white, you're looking at something else, possibly deadly. | Attached (adnate) to slightly free. Pale lilac-gray when young, darkening to dark purple-gray and finally purple-black as spores mature. Crowded and broad. |
| Stem | 3–10 cm tall, white, sturdy but not bulky. Has a thin, fragile ring partway up that often disappears with age. No volva (cup) at the base — this is critical. Death Caps have a volva; Field Mushrooms don't. | 6-15 cm tall, 1.5-3 cm thick. White, sturdy, solid when young (becoming hollow with age). Has a distinctive thick, double-edged ring with a grooved or cogwheel pattern on the upper surface. Base often has white rhizomorphs extending into the substrate. |
| Spore print | Dark chocolate brown — almost black. Drop it on white paper overnight. | Dark purple-brown to purple-black. |
| Odor | Pleasant, mushroomy. That classic 'fresh mushroom' smell you know from the grocery store. | Mild, pleasant, slightly earthy or potato-like. |
| Habitat | Grasslands, pastures, meadows, lawns, and parks — anywhere with rich soil and short grass. Loves fields grazed by horses and cattle. A saprobe that feeds on decaying organic matter in the soil, not on tree roots. Avoids dense forests. | Saprotrophic on wood chips, straw, composted garden debris, and other lignin-rich organic matter. Found in gardens, compost heaps, mulched beds, and agricultural settings. Prefers partially shaded, moist conditions. Widely cultivated in outdoor beds and permaculture gardens. |
| Season | Late summer through autumn. Peak fruiting after warm rain in August–October in the Northern Hemisphere. Can appear as early as June in mild years. | Late spring through autumn, with peak fruiting in late spring (May-June) and again in early autumn (September-October) in temperate regions. Cultivation beds may produce flushes from April through November depending on climate and moisture. |
Found one of these in the wild? Don't rely on memory — identify it from a photo with Orangutany and check it against both species before you touch it.