The morels and false morels have some similarity in general appearance. Fruitbodies normally have a distinct stipe (stem) and a head (cap) that is usually convoluted in some way. Spores are borne on the outer surface (or in large pits in the outer surface). Presently they fall into two families, Helvellaceae and Morchellaceae.

The Trial Key to HELVELLACEAE in the Pacific Northwest was written by Harold Treibs and covers Discina, Gyromitra, and Helvella.

There is no key yet to Morchellaceae for the good reason that the taxonomy is not worked out yet. It is easy to distinguish the thimble morels (Verpa conica and Verpa bohemica) from true morels (Morchella), but it is not clear yet how many common species of Morchella there are in the Pacific Northwest.

Morchella semilibera is an uncommon species that is easy to separate by the attachment of the head when cut lengthwise: the other morels in the Pacific Northwest have heads that are intergrown with the stem for most of the height of the head. Morchella semilibera has the lower part of the head (often as much as half of it) free of the stem. (Verpa species have a head that is free of the stem except right at the top of the stem.)

Morchella rufobrunnea is another uncommon species found in Oregon. It was described from Mexico in 1998 and is also found in California in landscaped areas and disturbed ground sites. A blushing reactioin to brown, brownish orange, brownish orange, pinkish red, or ferruginous occurs both in head and stem when the fruiting body is mature or injured.

For the other morels, pickers have referred for years to black morels, gray morels, green morels, pink morels, and yellow morels, but scientific delimitation for the actual species has been lacking.

Molecular research in the 1990s had suggested that the black morels (M. angusticeps, M. elata, M. conica) and the yellow morels (M. esculenta, M. crassipes, and M. deliciosa) are separate taxonomic groups (Bunyard et al.). (All of these names have been used in the past for variations of morels in the Pacific Northwest, but the names M. crassipes and M. deliciosa are not considered further here.) Immunological techniques suggested the the gray, tan, and large tan forms in the M. esculenta complex are immunologically indistinguishable and likely conspecific (Jung).

Pilz et al.(2003) identified 5 putative species with the aid of molecular techniques, PS A, PS B, PS C, PS D, and PS E, and they have field characters as follows.

PS D (black stocking morel, a common member of the "gray morel" grouping) has the surface of the stem distinctly velvety when young, dark brown to black (as opposed to color at all ages entirely off-white, ivory, tan, dull pink or dull purple). The stem becomes paler when old "as the velvety layer is stretched apart (use a hand lens to look for dark tufts of hyphae in old specimens)". This is one of the burn morels, fruiting the spring following a fire. It has been called Morchella atrotomentosa (see for example McKnight (1987), but there are nomenclatural problems with the use of that name. In 2008, Michael Kuo described this taxon as Morchella tomentosa.

PS C (known as green morel because of the olive-tinged gray or olive-tinged brown color of mature pits) and PS B (pink morel with mature pits rosy tan to pinkish brown), are burn morels in the black morel grouping.

PS A is a third member of the black morel grouping, called the natural black morel because it occurs away from fires: it has mature pits grayish tan or pale tan. The three black morels all key out to the M. elata (complex), M. conica, or M. angusticeps, depending on the reference used, [but all of these names are of uncertain application].

PS E (mountain blond morel) also occurs away from fires and has the ribs separating the pits lighter in color (ivory to nearly white) than the lining of the pits when old. By maturity the ribs are off-white sometimes with amber stains and bruises. Pits are gray when very young, becoming tan, golden, or straw yellow when mature. It differs from most descriptions of M. esculenta from Europe or elsewhere in North America in that 1) it has a relatively narrow head, rather than oval or rounded, especially in young specimens, 2) "the primary ribs are strongly vertical and relatively straight producing elongated pits rather than the rounded to somewhat irregular pits generally attributed to M. esculenta", and 3) it "seems to be characteristic of conifer forests including either lodgepole or ponderosa pine, whereas the complex centered on M. esculenta is commonly associated with hardwoods sometimes mixed with conifers."

Both PS E and a morel that fits the classic concept of M. esculenta occur in eastern Oregon.

In addition to these, black morels develop in burn areas earlier in the season than the gray and green members of the black burn morel group. They have light stems that fade to rusty brown, and the ridges turn black. There is often a taproot. (Larry Evans, speaking of Montana in particular, pers. comm.)

DESCRIPTIONS

Verpa bohemica (wrinkled thimble-morel)

HEAD 1-5 cm across and 2-5 cm high (sometimes larger), "bluntly conic to somewhat bell-shaped, squarish, or irregular", attached to stem only at the top, sometimes flaring or upturned when old; "pale to dark yellow-brown or tan", often darker brown when old; "deeply wrinkled by branching folds or ribs which are often vertically oriented and sometimes branch to form pits". STEM 6-15 cm x 0.8-3 cm (or sometimes much larger), whitish to cream or becoming tan or ocher when old; 'smooth or often roughened by small orangish to brownish granules which may form transverse belts or "ribs"'. FRUITING widely scattered to gregarious in woods, thickets, and forest edges, etc., usually fruiting in early spring, typically appearing 1-3 weeks before Morchella species. SPORES 54-80 x 15-18 um, asci 2-spored, (Arora). REMARKS The description is derived from Arora. Verpa conica has a smoother more irregularly wrinkled head and 8-spored asci.

Verpa bohemica Andrew Parker

Verpa conica (smooth thimble-morel)

HEAD 1-4 cm across and high, "usually more or less thimble-shaped (broadly conic to bell-shaped), but sometimes lobed" attached to stem only at top, often flaring out or turning up when old; ocher-brown to brown or dark brown; smooth to slightly wrinkled, or in one form irregularly wrinkled. STEM (2.5)4-12 cm x (0.4)0.5-1.5 cm, "white to yellowish, tan, or tinged ocher-orange"; "smooth or with granular or minutely scaly transverse bands or ribs (granules often browner or oranger than background)". FRUITING single, scattered, or gregarious in soil or humus in forests, riparian woodlands (by streams), under shrubbery and fruit trees, etc., usually in spring. SPORES 28-34 x 15-19 um, (Tylutki), 30-33 x 17-19 (R. Sieger, pers. comm. measured from eastern Washington), (20)22-30(34) x 12-17(19) um, elliptic, smooth, without oil droplets; asci 8-spored, (Arora), (17)20-25 x 11-15 um (Breitenbach & Kränzlin, Europe). REMARKS The description is derived from Arora. Verpa bohemica can look similar to the strongly wrinkled form of V. conica but has vertical ridges and very large spores in 2-spored asci.

Verpa conica Michael Beug

PS A (natural black morel)

HEAD "broadly rounded, conic to irregularly ellipsoid when young", often broadening especially near the stem as it matures. The ribs when young are shades of dull grayish tan, steely gray, or dark brownish gray becoming black by maturity; they are minutely and inconspicuously velvety when young, becoming dry and bald when old; the edges typically remain intact and sterile. Pits when young are dull grayish tan to steely gray, when old grayish tan or light brown. STEM "ivory to light tan or washed with dusky rose" when young, varying to tan or rosy tan when old; ornamentation never brown to black and the surface smooth at first, appearing granulose when old. HABITAT "on nonburned soils, litter, and duff including nonburned islands in burned areas or on burned soils but then apparently no sooner than the second spring after an intense wildfire". SPORES (23) 26-33 x 15-16(18) um. REMARKS The term “black morel” includes the one described here and the pink morel and green morel described below, and is sometimes used to include the black stocking morel. The Morel Data Collection Project, outlined in Kuo(2005) and Kuo(2006), includes several taxa that look similar to the natural black morel but can be distinguished by DNA methods, three to five according to the method used, and all recorded (among other places) in Oregon.

PS B (pink morel)

HEAD at first elongate conic with rounded conic top, sometimes expanding to broadly conic when old. Ribs are cream-colored to pale shell-pink when young, typically black well before maturity; they are not conspicuously velvety when young and become dry and bald when old; the edges typically remain intact, sometimes with a fertile strip down the center. Pits when young are "cream-colored to dusky pink or pinkish tan", when mature becoming "pinkish tan to light pinkish brown". STEM white or nearly so at all ages; ornamentation never brown to black, and surface smooth at first, becoming slightly granulose in age. HABITAT "restricted to burned plots, presumably burned soils, the first spring/summer after a fall fire and were not found the second year after a fire". SPORES 21-24 x 13-16 um.

PS C (green morel)

HEAD at first elongate conic with rounded conic top, sometimes expanding to broadly conic when old. Ribs are gray when young, becoming black well before maturity; they are not conspicuously velvety when young and become dry and bald when old; edges typically remain intact, sometimes with a fertile strip down the center. Pits when young are dark gray to dark olive gray, when old olive gray to olive brownish gray. STEM white or nearly so at all ages; ornamentation never brown to black, and surface smooth at first, becoming slightly granulose in age. HABITAT "restricted to burned plots, presumably burned soils, the first spring/summer after a fall fire and were not found the second year after a fire". SPORES 20-24 x 13-16 um.

Morchella tomentosa - PS D (black stocking morel)

HEAD elongate-ovoid to nearly columnar, expanding variously when old. Ribs when young are silvery gray to charcoal gray, at maturity gray to black where intact; when young ribs are conspicuously velvety/hairy, the hairs collapsing when old; edges are "extremely fragile, soon cracking and breaking away to expose the white to ivory underlying tissue, lacking fertile tissue". Pits when young are deep gray to nearly black, when old varying from gray to grayish tan. STEM charcoal gray to nearly black when young becoming pale gray to grayish tan when mature. When young it is densely velvety from projecting hyphae; when old the velvety layer stretches apart "leaving tufts of brown hyphal tips on an ivory, off-white, or pale tan background". HABITAT fruits the year after a wildfire. SPORES 19-25 x 13-16 um. REMARKS Other names applied to this taxon are “black foot morel” and “fuzzy-foot”. It has been called a “gray” morel, but that term is applied by different people to different morels. The term “gray” is sometimes used of yellow morels at a certain stage of development or under certain ecological conditions.

PS E (mountain blond morel)

HEAD "columnar to narrowly obtusely conic when young, variously expanding with maturity but typically remaining relatively narrow in relation to height". Ribs when young pale grayish tan, when old ivory to pale tan and then often with rusty ocher stains; they are essentially bald when young, in age becoming dry and waxy; edges typically remain intact and sterile. Pits when young are light smoky gray, when old near straw color or the color of a manila folder. STEM ivory to cream-colored, sometimes with rust-colored or amber discolorations. Surface is bald. HABITAT "on nonburned soils in living forests or in nonburned areas within the fire perimeter". SPORES 23-26(28) x 14.3-16(18) um. REMARKS Kuo (2006) calls this the western blond morel “to reflect the fact that the Western Blond is found not only under conifers at high elevations but also under hardwoods at lower elevations”. The colors, he says, suggest a yellow morel, since the ridges do not darken with age and the overall color of the head is fairly pale throughout development--though the mature head colors are just a little bit browner than the colors of the typical yellow morel. The stature of the Western Blond, however, ‘suggests a black morel; the pits and ridges are more vertically arranged than those of the esculenta-like yellow morels, and the cap attaches to the stem with a shallow "rim"--a feature not usually found with yellow morels.’

Morchella esculenta (yellow morel)

HEAD 2-7(8) cm across at widest part, 2-10(17) cm high, hollow, lacking prominent free margin (tissue intergrown with stem), oval to nearly cylindric or slightly narrowing towards top but seldom strongly conic, outer surface composed of pits and ridges, pits "generally more round than elongate in outline at maturity", then often 0.4-4 cm long and 0.3-1.5 cm wide, lined by spore-bearing tissue, main ridges to 1.5 cm high and 0.3 cm wide; pits "when very young pale dingy grayish tan, soon developing strong gray tones as the pits open up, these fading and usually replaced by tan, dull ochraceous, or golden tan colors by the time spores are mature", ridges at first colored as pits and close together, as head expands becoming paler than the pits, "usually white to creamy white then stained rusty yellow or dingy brown", but where the surface of the ribs flakes or tears away and exposes the underlying tissue, again colored as pits; surface of ribs more waxy than velvety.STEM 2.5-8(10) cm x 2-4.5 cm, hollow, equal to widening slightly downwards, basically round in cross-section, base "often enlarged and appearing pleated or gathered"; "off-white to ivory or pale cream color"; finely pruinose at first, surface "stretched" apart when old. FRUITING single to gregarious or clustered, "in a wide variety of habitats, including hardwood forests", "under mature to old fruit trees (especially apples), around dead American elms, under white pines, on sand dunes and many other places". SPORES 21-25(28) x 12-16 um. REMARKS This description is derived from Weber 1988. Morels fitting this description occur widely in North America and appear to comprise at least three genetically distinct kinds. See above for the comparison to the mountain blond morel. The name “Morchella crassipes” has been used to refer to a yellow morel found late in the season with a swollen stem, but these have often proven to be a growth form of the yellow morel.

Morchella esculenta Pamela Kaminski

Morchella rufobrunnea (blushing morel)

HEAD (2.0)3.0-4.5(5.0) cm across, (4.0)6.0-8.5(12.0) cm high, conic to ovoid or nearly cylindric, with longitudinal ridges and transverse veins forming short or long pits extended vertically but when old the vertical configuration of the ribs somewhat lost and forming a wrinkled head; when young gray to grayish, with whitish to grayish ribs, when mature completely yellowish, brownish, or brownish yellow; blushing when injured or in maturing in irregular small spots, brown, brownish orange or pinkish red, to ferruginous, sometimes in old specimens almost completely reddish brown. STEM (2.0)3.0-7.0(9.0) cm x 1.0-2.5 cm, cylindric or wider at base, "irregularly wrinkled mainly toward the base"; whitish to cream or pale grayish, darker toward the base, yellowish in old specimens; blushing when injured or in maturing in the same way as head; covered by minute granules toward the stem top. FRUITING disturbed ground sites and landscaped areas. SPORES (19)20-24(25.5) x (13)14-16(17) microns, but in immature fruitbodies (11)14.5-19(20) x (8)9-10(11) um.

Morchella semilibera (half-free morel)

HEAD 1.5-3 cm across, 1.5-4 cm high at maturity, when young often taller than broad and nearly cylindric to broadly conic with rounded to truncate top, when old broader than tall, ribbed and pitted at all stages, lower part of head and margin (often as much as half of the head) free of stem and forming a skirt around upper part of stem, the rest above the top of the stem, pits typically longer than broad especially toward the margin, pits grayish tan to tan when mature, when old ribs darkening to dark grayish brown or black. STEM (1.5)4-10(15) cm x 1.5-3(4) cm, hollow, barely visible below head when young, elongating to 2.5-3(4) times as long as the head when mature, more or less equal when young, often widening downwards when old, low longitudinal ribs often present when old; "ivory white to dull creamy yellow"; scurfy. FRUITING single to gregarious on the ground; in western North America "it occurs under conifers, cottonwoods, and alders". SPORES (19.5)22.5-26(30) x (12)14-17(21) um, oval. REMARKS The description derived from Weber (1988). Morchella semilibera has the general appearance of more common morels but distinguished by the attachment of the head when cut lengthwise: the other morels in the Pacific Northwest have heads that are intergrown with the stem for most of the height of the head, but Morchella semilibera has the lower part of the head (often as much as half of it) free of the stem. Verpa species have a head that is free of the stem except right at the top of the stem.

Morchella semilibera Ben Woo

Note on “Morchella deliciosa” and Morchella rufobrunnea
The other yellow morel name commonly found in field guides, Morchella deliciosa, refers properly to a kind not documented as a western North American species. The Morchella deliciosa that was described by Fries in Europe and for North American by Weber in 1995 is documented only for eastern North America. According to Kuo (2005), the mushrooms are small in comparison to the classic North American yellow morels, and the pits and ridges are sparser proportionally and more vertically arranged. Additionally the heads are frequently but not always more pointed. What has passed for Morchella deliciosa in California is thought to be Morchella rufobrunnea (the blushing morel), described from Mexico in 1998. The trademark physical features of Morchella rufobrunnea, according to Kuo (2006) are the frequently pointed head (especially when young), the striking contrast of the light-colored, vertically arranged ridges and darker pits in young mushrooms, and the fact that it is rufescent, meaning that it blushes pinkish to salmon orange when bruised, especially when young. To complicate things further, says Kuo, ‘some authors (including Lincoff, 1992; Bessette, Bessette & Fischer, 1997; and Roody, 2003) describe a large, white morel with dark pits as "Morchella deliciosa" in an erroneous interpretation of Fries's original description. Kuo maintains that the mushrooms described by these authors are probably merely immature forms or ecotypes of the yellow morel.

REFERENCES

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