Slender Parasol

Description

The slender parasol is a slender parasol mushroom with a cap 5–12 cm across. When young it is ovoid, later convex to flat, with a distinct umbo in the centre. It is light brown or ochre, darker in the centre, and finely scaly towards the edges. The gills are white and do not reach the stem. The stem is 10–15 cm tall, thin, fibrous and pale brownish, swollen into a small bulb at the base, with a movable, double ring. The flesh is white, with a mildly nutty taste.

It grows from August to November in open deciduous and coniferous forests, at their edges and along forest tracks. In Poland it is fairly rare, though in places it is encountered more often.

It differs from the parasol mushroom (Macrolepiota procera) in its smaller, slenderer fruiting body and fine scales instead of thick, tile-like ones. Parasol mushrooms are sometimes confused with poisonous species, so collect only specimens you are certain about. Fruiting bodies with a ring and a bulbous stem base can also be confused with some poisonous dapperlings and amanitas.

Identification features

Cap

Diameter 5–12 cm; ovoid when young, later convex to flat, with a distinct prominent umbo in the centre (hence the epithet “mastoidea”, breast-shaped). Colour light brown or pale flesh-ochre; some descriptions give whitish with brown scales in the centre. The surface is initially cracked in a star-like pattern; in mature fruiting bodies it stays that way only in the centre, where it is also darker. Away from the centre the cap is finely, densely, radially and granularly scaly, with a paler background showing between the scales.

Hymenophore (underside of the cap)

Gills free, i.e. not reaching the stem, white.

Stem

Height 10–15 cm, thickness 0.8–1.5 cm, cylindrical, with a bulbous swelling at the base (up to 2.5 cm). Surface smooth or slightly streaked, the colour of pale, brownish wood. The stipe is fibrous and tubular (hollow inside) and can be pulled out of the cap. Ring distinct, double, movable.

Flesh

Whitish, with a mildly nutty taste. No data on smell or colour changes. Do not taste the flesh of unknown mushrooms.

Spore print and spores

Spore print white. Spores 13–16(–18) × 7–9.5(–11) µm.

Habitat and distribution

Ecology. Saprotroph, growing in open deciduous and coniferous forests, at their edges and along forest tracks.

Distribution. A European species. In Poland it is recorded throughout the country; it is fairly rare, locally fairly common. It is not on the list of threatened species and is not legally protected in Poland.

Fruiting. From August to November.

What can it be confused with?

• Macrolepiota procera (parasol mushroom) — Larger fruiting bodies, cap covered with thick, overlapping, tile-like scales.
• Macrolepiota excoriata (Polish: czubajka białotrzonowa) — Paler stem and cap scales.
• Poisonous Chlorophyllum species — They resemble parasol mushrooms and can be confused with them. If you are not certain of the features (ring, spore print, flesh colour changes), do not collect.
• Dapperlings (Lepiota) — Fruiting bodies are usually smaller; among the dapperlings are poisonous species, including deadly ones. The slender parasol has a cap 5–12 cm across and a stem 10–15 cm tall.

Never rely on a single feature. If you are not sure — do not pick it; show the mushroom to a qualified mushroom expert.

Interesting facts

• The epithet mastoidea refers to the shape of the umbo on the cap, which resembles a breast.
• The species was described in 1821 by Elias Fries as Agaricus mastoideus, and its current genus name was given by Rolf Singer in 1951.
• It has about 22 Latin synonyms, and in Polish literature it has gone by several names, including czubajka wysmukła and kożuszek.
• In 2025 the nomenclature commission recommended the name czubajka wątła for the synonym Macrolepiota affinis.