Half-free morel

Description

The half-free morel is a spring fungus with a conical or bell-shaped cap 2–8 cm tall. Its surface is covered with vertical ridges and shallow pits, in colours from yellow-brown to olive-brown, and the ridges are almost black. A characteristic feature is that the lower part of the cap, from one third to half of its height, is free and hangs around the stem like a bell. The stem is tall, whitish to ochre, hollow inside and very brittle.

It grows in spring in fertile, moist and shady forests, in riverside thickets, in parks and gardens, often under ash trees. In Poland it is rare, so finding one is more of an exception.

You can tell it from the black morel by its partly free cap and smooth stem, and from the early false morel by the structure of the cap: in the false morel it is attached only at the very top and does not have such distinct pits. A cross-section shows that the whole fruiting body is hollow inside. If you are not sure of the species, do not collect or eat it.

Identification features

Cap

Cap bell-shaped to bell-conical, rounded when young; height 2–8 cm, width up to about 5 cm (descriptions give different ranges), very variable between specimens. It is attached to the stem only by its upper part; the lower 1/3 to 1/2 is free. The surface is ribbed: between tall, thin, vertical ridges lie pits arranged in vertical rows, separated by low cross-ridges. The pits are yellow-brown, light brown to olive-brown; the ridges and cross-ridges are dark brown to blackish brown, blackish when dry. The underside of the cap is whitish.

Hymenophore (underside of the cap)

The hymenophore (spore-bearing layer) covers the inside of the pits on the cap surface; there are no gills or tubes. The ridges and cross-ridges are sterile and darker than the pits.

Stem

Height 5–12 cm, thickness 1–3 cm (up to about 2.5 cm in some descriptions), hollow inside, very brittle. Tall in relation to the cap. The surface is smooth, bare, grooved in mature specimens; at first whitish, then yellowish or ochre (buff). In old specimens the cap is proportionally smaller relative to the stipe, which makes the fungus resemble species of the genus Verpa.

Flesh

Thin (2–3 mm), waxy, brittle, white. The smell is pleasant, spicy, fairly strong. Do not taste the flesh raw.

Spore print and spores

Spore print olive-yellow to pale ochre. Spores ellipsoid, hyaline, smooth, without guttules, 20–30 × 12–18 µm.

Habitat and distribution

Ecology. A terrestrial fungus, probably a saprotroph. It grows singly or in groups in fertile, moist and shady forests, riverside thickets, woodlots, parks and gardens; often under ash trees.

Distribution. Europe and Asia (some descriptions also give North America, although the half-free morels there are now regarded as separate species). In Poland it occurs throughout the country, but is rare; about 100 localities are known. On the Red List of Plants and Fungi of Poland it is in category R (rare, potentially threatened because of its limited range and small habitat areas). From 1983 to 2014 it was under strict protection; since 2014 it has been under partial protection (Dz.U. 2014 item 1408, listed as Morchella gigas): specimens growing outside gardens, horticultural crops, forest nurseries and green areas are protected.

Fruiting. Spring (usually April–May).

What can it be confused with?

• Morchella elata (black morel) — The cap is attached to the stem along the entire length of its lower margin (it is not partly free); the stem is mealy-dusted and granular.
• Verpa bohemica (early false morel) — The cap is attached to the stem only at the apex and hangs down like a hood, the surface is wrinkled rather than having distinct pits; the stem is filled with a cottony pith inside.

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 species was described by Augustin Pyramus de Candolle in 1805; for a long time it was placed in the genus Mitrophora as the half-free morel, and this name still appears in older literature.
• DNA analyses have shown that half-free morels, almost identical macroscopically, form a complex of at least three distinct species: European, western North American (Morchella populiphila) and eastern North American (M. punctipes).
• In Poland it was under strict protection from 1983 to 2014, and on the Red List of Plants and Fungi it is in category R.
• It often occurs under ash trees, and the fruiting bodies appear in spring.