 = Verpa bohemica = 
 
 Verpa bohemica is a species of fungus in the family <unk> . Commonly known as the early morel ( or early false morel ) or the wrinkled thimble @-@ cap , it is one of several species known informally as a " false morel " . The mushroom has a pale yellow or brown thimble @-@ shaped cap — 2 to 4 cm ( 0 @.@ 8 to 1 @.@ 6 in ) in diameter by 2 to 5 cm ( 0 @.@ 8 to 2 @.@ 0 in ) long — that has a surface wrinkled and ribbed with brain @-@ like <unk> . The cap hangs from the top of a lighter @-@ colored , brittle stem that measures up to 12 cm ( 4 @.@ 7 in ) long by 1 to 2 @.@ 5 cm ( 0 @.@ 4 to 1 @.@ 0 in ) thick . <unk> , the mushroom is distinguished by its large spores , typically 60 – 80 by 15 – 18 µm , and the presence of only two spores per <unk> . 
 In the field , the mushroom is reliably distinguished from the true morels on the basis of cap attachment : V. bohemica has a cap that hangs completely free from the stem . Although widely considered edible , consumption of the mushroom is generally not advised due to reports of poisoning in susceptible individuals . <unk> symptoms include gastrointestinal upset and lack of muscular coordination . V. bohemica is found in northern North America , Europe , and Asia . It fruits in early spring , growing on the ground in woods following the snowmelt , before the appearance of " true morels " ( genus Morchella ) . The synonym Ptychoverpa bohemica is often used by European <unk> . 
 
 = = Taxonomy , phylogeny , and naming = = 
 
 The species was first described in the scientific literature by the Czech physician and mycologist Julius <unk> von <unk> in 1828 , under the name Morchella bohemica . The German naturalist Joseph Schröter transferred it to the genus Verpa in 1893 . Ptychoverpa bohemica is a synonym that was published by Frenchman Jean Louis Émile <unk> in his 1907 treatise on the <unk> of Europe ; the name is still occasionally used , especially in European publications . <unk> believed that the large , curved <unk> and the rare and short paraphyses were sufficiently distinct to warrant a new genus to contain the single species . Ptychoverpa has also been classified as a section of Verpa . The section is characterized by the presence of thick longitudinal ridges on the cap that can be simple or forked . 
 The specific epithet bohemica refers to Bohemia ( now a part of the Czech Republic ) , where <unk> originally collected the species . The mushroom is commonly known as the " early morel " , " early false morel " , or the " wrinkled thimble @-@ cap " . Ptychoverpa is derived from the Ancient Greek <unk> ( genitive form <unk> ) , meaning " fold " , layer " , or " plate " . 
 
 = = Description = = 
 
 The cap of this fungus ( known technically as an <unk> ) is 2 to 4 cm ( 0 @.@ 8 to 1 @.@ 6 in ) in diameter by 2 to 5 cm ( 0 @.@ 8 to 2 @.@ 0 in ) long , with a conical or bell shape . It is folded into longitudinal ridges that often fuse together ( <unk> ) 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 cm ( 2 @.@ 4 to 4 @.@ 7 in ) long by 1 to 2 @.@ 5 cm ( 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 <unk> with <unk> hyphae , it eventually becomes hollow in maturity ; overall , the mushroom is rather fragile . The spore deposit is yellow , and the flesh is white . 
 Relative to other typical mushroom species , the spores of V. bohemica are huge , typically measuring 60 – 80 by 15 – 18 µm . They are elliptical , smooth , sometimes curved , and appear hyaline ( translucent ) to yellowish . The spores , which number two ( more rarely three ) per <unk> are characteristic for this species . The smooth , elliptical asci measure 275 – 350 µm long by 16 – 23 µm wide . The British @-@ Canadian mycologist Arthur Henry Reginald <unk> determined that the asci are <unk> — they bend toward light . As he noted , " I cut transverse sections though their <unk> , examined these sections under the microscope , and at once perceived that in all the <unk> grooves and depressions the asci were curved outwards so that their <unk> must have faced the strongest rays of light to which the ends of the asci has been subjected in the places where the fruit @-@ bodies developed . " This response to the stimulus of light is significant because it permits a fruit body to point and later discharge its asci towards open spaces , thus increasing the chances that the spores will be dispersed by wind . The paraphyses are thick and club @-@ shaped , with diameters of 7 – 8 µm at their tips . 
 
 = = = 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 <unk> esculenta . The responsible <unk> in G. esculenta is <unk> ; it is suspected that V. bohemica may be able to synthesize low levels of the <unk> . Over @-@ consumption of the mushroom has been reported to have induced a coma . Those who do wish to eat this species are often advised to <unk> with copious quantities of water ( discarding the water before consumption ) , to dry the specimens before eating , or , if eating for the first time , to restrict consumption to small portions to test their tolerance . Some advocate only eating the caps and discarding the stems . Opinions on the flavor of the mushrooms vary , ranging from " strong but not on a par with true morels " , to " pleasant " , to " not distinctive " . 
 
 = = = Similar species = = = 
 
 The closely related species Verpa <unk> typically has a smooth cap , although specimens with wrinkled caps are known . V. <unk> may be distinguished microscopically by its eight @-@ spored asci . Its North American range extends much further south than V. bohemica . Another similar group of species are the " half @-@ free " morels , Morchella semilibera and others , which have a <unk> 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 @-@ <unk> stem of a specimen of M. semilibera is hollow , while V. bohemica usually has <unk> <unk> in the stem , and M. semilibera usually has vertical <unk> near the base , while V. bohemica lacks them . Verpa bohemica may be reliably distinguished from all similar species by its much larger spores . 
 
 = = Ecology , habitat and distribution = = 
 
 The fruit bodies of V. bohemica grow singly or scattered on the ground in woods in early spring , often before the appearance of the morel , and throughout the morel season . It is often found along riverbanks , near <unk> , willows and <unk> , often buried in plant litter . The fungus prefers to fruit in moist areas with ample sunlight . Its minimum growth temperature is 3 ° C ( 37 ° F ) , with an <unk> of 22 ° C ( 72 ° F ) , and a maximum of about 30 ° C ( 86 ° F ) . A study of carbon and nitrogen isotope ratios indicated that Verpa bohemica is saprobic , that is , obtaining nutrients from decomposing organic matter . It has been suggested , however , that the fungus is mycorrhizal for at least part of its life cycle . The fungus has a wide distribution throughout northern North America ; its range extends south to the Great Lakes in the Midwestern United States , and south to northern California on the West Coast . In Europe , the fungus is widely distributed , and has been collected from Austria , the Czech Republic , Denmark , Finland , Germany , Norway , Poland , Russia , Slovenia , Spain , Sweden , and the Ukraine . In Asia , it has been recorded from India and Turkey . 
 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 , appearing shortly after leaves begin to form on deciduous trees . <unk> @-@ head morels ( Morchella <unk> ) fruit next , followed by the yellow or white morels ( Morchella esculenta ) , then <unk> Morchella <unk> . The fruit bodies serve as a habitat for breeding <unk> ( flies ) , including <unk> media , <unk> <unk> , and <unk> <unk> . 
 
 