Agaricus abruptibulbus or Horse mushroom
How they differ, how to recognize them and which is more dangerous — a mushroom comparison
The short answer
Agaricus abruptibulbus and Horse mushroom are similar species that can be mixed up while foraging. The main visible difference: use: Agaricus abruptibulbus — cook fresh, drying, Horse mushroom — cook fresh, drying, pickling. The mushrooms also differ in the following features: size, cap shape, cap surface.

Agaricus abruptibulbus
Agaricus abruptibulbus

Horse mushroom
Agaricus arvensis
📊 Comparing characteristics
| Characteristic | Agaricus abruptibulbus | Horse mushroom |
|---|---|---|
| Edibility class | Agaricus abruptibulbus Edible | Horse mushroom Edible |
| Season | Agaricus abruptibulbus SummerAutumn | Horse mushroom SummerAutumn |
| Use | Agaricus abruptibulbus Cook freshDrying | Horse mushroom Cook freshDryingPickling |
| Size | Agaricus abruptibulbus Medium (5–15 cm) | Horse mushroom Large (over 15 cm) |
| Cap color | Agaricus abruptibulbus WhiteCream | Horse mushroom WhiteCream |
| Cap shape | Agaricus abruptibulbus ConvexFlat | Horse mushroom Convex |
| Cap surface | Agaricus abruptibulbus SmoothFibrous | Horse mushroom Smooth |
| Taste | Agaricus abruptibulbus Mild | Horse mushroom Mild |
| Smell | Agaricus abruptibulbus Anise | Horse mushroom PleasantAniseAlmond |
| Flesh color change | Agaricus abruptibulbus Yellowing | Horse mushroom Yellowing |
| Hymenophore | Agaricus abruptibulbus Gilled | Horse mushroom Gilled |
| Stem | Agaricus abruptibulbus Central | Horse mushroom Central |
| Ring (veil) | Agaricus abruptibulbus Ring present | Horse mushroom Ring present |
| Volva | Agaricus abruptibulbus No volva | Horse mushroom No volva |
| Substrate | Agaricus abruptibulbus SoilForest litter | Horse mushroom SoilDung |
| Nutrition type | Agaricus abruptibulbus Saprotroph | Horse mushroom Saprotroph |
| Partner trees | Agaricus abruptibulbus SpruceBeech | Horse mushroom — |
📅 Seasonality
Agaricus abruptibulbus
Fruiting season
July – October
Horse mushroom
Fruiting season
June – November
🔬 Morphology
Cap
Agaricus abruptibulbus
The cap of Agaricus abruptibulbus reaches 5 to 12 centimeters across. When young it is bell-shaped or cylindrical, opening out with age to convex and flat. The surface is smooth, silky-fibrous, dry, pure white or cream; it slowly turns yellow when touched and with age, especially at the margin. Yellowing on touch is an important diagnostic feature.
Horse mushroom
Cap 6-20 cm across; in young mushrooms firmly hemispherical to egg-shaped, the margin often rolled under. Later it becomes convex to flat. Color pure white to cream, with subtle yellowish tints in old mushrooms; spots yellow to ocher when touched. Surface smooth, slightly sticky in wet weather, dry and matte in dry weather. Sometimes with fine fibrous scales in the center.
Hymenophore
Agaricus abruptibulbus
The hymenophore is gilled. The gills are free, not attached to the stem, and very crowded. Their color changes with age: in young mushrooms they are pale pink or grayish-pink, later darkening to chocolate brown and almost black. The spore print is dark brown. The pinkish young gills are the key feature that distinguishes Agaricus from the white-gilled, deadly poisonous amanitas.
Horse mushroom
Gilled hymenophore — gills free, crowded. When young — grayish-white, with a pinkish tinge, becoming with age dark brown, chocolate-blackish. Spore print dark brown.
Stem
Agaricus abruptibulbus
The stem is slender, white, 6 to 12 centimeters tall; its defining trait is an abruptly widened, rounded bulb at the base, as if cut off. In the upper part there is a large hanging ring — a trace of the veil. The stem may turn yellow when touched. There is no true sac-like volva at the base; do not mistake the distinct bulb of this Agaricus for an amanita's volva.
Horse mushroom
Stem 6-12 cm tall, 1.5-3 cm thick, thick, fleshy, cylindrical, slightly thickened at the base. Color white to cream. On the upper part — a large membranous double ring with a characteristic "toothed" lower edge (like a cogwheel) — a diagnostic feature of the species.
Flesh
Agaricus abruptibulbus
The flesh is white and thin, slowly turning yellow when cut, especially at the base of the stem. The taste is mild and pleasant, with no bitterness. Its main hallmark is a sweetish aroma of anise or bitter almond, which distinguishes this species from its unpleasant-smelling yellow-staining lookalike.
Horse mushroom
Flesh firm, meaty, white; when cut it slowly yellows in the flesh of the cap and upper stem. Does not redden (unlike A. silvaticus). The smell is a distinct anise-almond — a characteristic feature of the species.
Smell
Agaricus abruptibulbus
The smell is pleasant, sweetish, of anise and almond — one of the defining features of the species. But if the mushroom smells of ink or carbolic, and the base of the stem turns bright yellow when cut, it is the poisonous yellow stainer, and you must not pick it.
Horse mushroom
Distinctly anise-almond, fruity — the most characteristic diagnostic sign. It comes out when you rub the flesh between your fingers. This smell is one of the most pleasant mushroom experiences in field foraging.
📍 Habitats
Agaricus abruptibulbus
Horse mushroom
👀 Similar mushrooms — don't mix them up!
Wood mushroom
EdibleHorse mushroom
EdibleThe prince
EdibleDeath cap
Deadly poisonousYellow stainer
PoisonousField mushroom
EdibleBlushing wood mushroom
EdiblePavement mushroom
EdibleDeadly fibrecap
Deadly poisonousLivid pinkgill
PoisonousGypsy mushroom
EdibleMacro mushroom
EdibleAgaricus abruptibulbus
EdibleAgaricus comtulus
EdibleAgaricus tabularis
EdibleSpotted toughshank
Inedible❓ Frequently asked questions
Can Agaricus abruptibulbus and Horse mushroom be mixed up?
How to tell Agaricus abruptibulbus from Horse mushroom?
Is Horse mushroom edible?
When do Agaricus abruptibulbus and Horse mushroom grow?
Sources
- [1]Вікіпедія (українська)
- [2]Атлас грибів України, Зеров Д.К. (1979)
- [3]MycoBank Database
- [4]Index Fungorum
- [5]GBIF
- [6]iNaturalist Ukraine