Verpa bohemica

Verpa bohemica is a saprobic species of fungus in the family Morchellaceae. Commonly known as the early morel (or early false morel) or the wrinkled thimble-cap, V. bohemica is one of several species known informally as a "false morel". It can be recognized in the field by the pale yellow or brown thimble-shaped wrinkled cap attached to the top of the lighter-colored stem; its distinguishing characteristic is its relatively large spores, typically 60–80 by 15–18 µm. Although widely consumed, edibility is generally not advised due to reports of poisoning in susceptible individuals. The synonym Ptychoverpa bohemica is often used by European mycologists.

Description

The cap of this fungus (technically an apothecium) is 2 to 4 centimetres (1 to 2 in) in diameter by 2 to 5 centimetres (1 to 2 in) long, with a conical or bell shape. It is folded into longitudinal ridges that often fuse together (anastomose) in a vein-like network. The cap is attached to the stem at the top only–hanging from the top of the stipe, with the lobed edge free from the stem– and varies in color from yellowish-brown to reddish-brown; the underside of the cap is pale. The stem is 6 to 12 centimetres (2 to 5 in) long by 1 to 2.5 centimetres (0.4 to 1.0 in) thick, cream-white in color, and tapers upward so that the stem is thicker at the base than at the top. Although the stem is initially loosely stuffed with cottony hyphae, it eventually becomes hollow in maturity; overall, the mushroom is rather fragile. The spore deposit is yellow. The flesh is white; the taste and odor of this species have been described as "pleasant".

Microscopic characteristics

Relative to other typical mushroom species, the spores of V. bohemica are huge, typically 60–80 by 15–18 µm; they are elliptical, smooth, sometimes curved, and appear hyaline to yellowish; the spores do not contain oil droplets. The "enormous" spores, which number two (more rarely three) per ascus are characteristic for this species.

Habitat and distribution

This species grows singly or scattered on the ground in woods in early spring, often before the appearance of the morel, but growing throughout the morel season. It is often found along riverbanks, near cottonwoods, willows and aspens, often buried in plant litter. A study of carbon and nitrogen isotope ratios suggests that Verpa bohemica is saprobic, that is, obtaining nutrition from decomposing organic matter. V. bohemica has a wide distribution throughout northern North America, and is also found in Europe.

A 10-year study of the distribution, time of fruiting and habitats of morel and false morel population in Iowa showed that early false morels are the first morels to fruit in the spring, shortly after leaves begin to form on deciduous trees. Narrow-head morels (Morchella angusticeps) fruit next, followed by the yellow or white morels (Morchella esculenta), then lastly Morchella crassipes.

Edibility

The edibility of this species is questionable; although Verpa bohemica is eaten by many, consumption of large amounts in a single sitting, or on successive days, has been reported to cause poisoning in susceptible individuals. Symptoms include gastrointestinal upset and lack of muscular coordination, similar to the effects reported by some individuals after consuming the false morel species Gyromitra esculenta. Those who do wish to eat this species are often advised to parboil with copious quantities of water (discarding the water before consumption), or to dry the specimens before eating.

Similar species

The closely related species Verpa conica typically has a smooth cap, although specimens with wrinkled caps are known. Another similar species is the "half-free morel", Morchella semilibera, which has a honeycombed cap that is attached to the stalk for about half of its length, and with ridges that are darker than the pits. Additionally, a cross-sectioned stem of a specimen of M. semilibera is hollow, while V. bohemica usually has cottony wisps in the stem. Verpa bohemica may be reliably distinguished from all similar species by its much larger spores.

Translation

The phrase "Verpa bohemica" occurs as such in the following languages: English, Piedmontese.

Translation(s) in other languages: German: Runzelverpel, Italian: Ptychoverpa bohemica, Lithuanian: Bohemiškasis aukšliavarpis, Polish: Naparstniczka czeska, Russian: Шапочка сморчковая, Slovak: Smrčkovec český, Serbian: Чешка смрчковица.