Journal of the Oklahoma Native Plant Society, Volume 8, Number 1, December 2008 57 Oklahoma Native Plant Record Volume 8, Number 1, December 2008 Ovrebo & Weber https://doi.org/10.22488/okstate.17.100062 Common Spring Mushrooms of Oklahoma Clark L. Ovrebo Nancy S. Weber Department of Biology Department of Forest Ecosystems University of Central Oklahoma and Society Edmond, OK 73034 Oregon State University E-mail: covrebo@uco.edu Corvallis, Oregon 97331 INTRODUCTION Springtime brings a resurgence of greenery and wildflowers to the landscape. For those interested in fungi it is time to look for mushrooms as well. In Oklahoma spring mushrooms appear for approximately two to three-weeks from late March to mid-April. The exact time depends on temperature, moisture, and in which corner of the state you hunt mushrooms. Collectors might encounter a few of the “gilled mushrooms”, Basidiomycota, during the spring, but it is the members of the phylum Ascomycota, often referred to as “Ascomycetes”, that are the most prominent and popular of the spring fungi. Here, we present a selection of common ascomycetes in the order Pezizales, the morels and related cup-fungi that you may encounter in the spring woods. The Ascomycota includes a diverse group of fungi ranging from yeasts to devastating plant pathogens, to edible wild mushrooms. Members of this phylum bear their spores in microscopic sac-like structures called asci. Some ascomycetes form fruiting bodies called ascocarps or ascomata. In the order Pezizales, the basic form of the ascocarp is called an apothecium. Apothecia resemble a cup or saucer with the asci lining the cup or covering the upper surface of the saucer; these fungi are often referred to as “cup-fungi.” In some species the apothecium has a stalk or stem. In others the apothecium may be recurved or contorted into any of a number of shapes including thimbles and pitted or wrinkled caps. Below we provide photographs and brief descriptions of the more commonly encountered spring-fruiting members of the Pezizales. More details can be found in most mushroom field guides. Common names, where known, are given in parentheses. We are hesitant to provide information on edibility. Great care must be taken to be absolutely sure of a mushroom’s identity. Only after becoming proficient at identifying mushrooms, and only then, can one determine edibility. Vouchers for specimens described here are housed in the mycological collection of the University of Central Oklahoma’s herbarium (CSU). Order Pezizales Morchella esculenta (common, yellow or tan morel) This is by far the most popular spring mushroom collected for consumption. It is recognized by its pitted cap with light tan or gray pits separated by creamy-white ribs when young. The ribs do not blacken at maturity. The entire length of the cap is attached to the stalk and both the cap and stalk are hollow. Two slightly different forms of this species are illustrated. One has a more rounded cap (Fig. 1) and the other is more tapered (Fig. 2). The morphological variation within this species needs further investigation, so we cannot be certain whether these variations represent distinct species. Websites such as www.mushroomexpert.com/morchella_yello w.html can offer more information. The common morel is usually found in wooded areas. River bottom forests seem to be good places in Oklahoma for finding morels. We have frequently found morels near eastern red cedar trees as well. Don’t count out metropolitan areas. The first author has found them in his own yard and on the University of Central Oklahoma campus. 58 Oklahoma Native Plant Record Volume 8, Number 1, December 2008 Ovrebo, C.L. Figure 1 Morchlla esculenta with rounded cap. Figure 2 Morchella esculenta with tapered cap. Morchella semilibera (half-free morel) It fruits at about the same time as the common morel and differs from the common morel by the way that the cap is attached to the stalk (Fig. 3). The lower half of the cap is free from the stalk and resembles a skirt. The ribs of the cap turn dark brown to black with age and the caps are often darker and smaller than those of the common morel. Figure 3 Morchella semilibera Gyromitra caroliniana Gyromitra c. is by far the largest spring mushroom found in Oklahoma (Fig. 4). The cap is brownish red and convoluted or brain- like. The stalk is robust with the exterior formed into irregular, rounded ridges separated by irregular grooves. The inside tissue of the cap and stalk appears to be stuffed with folded or convoluted tissue (Fig. 5). Figure 4 Gyromitra caroliniana external view Figure 5 Gyromitra caroliniana showing internal structure 59 Oklahoma Native Plant Record Volume 8, Number 1, December 2008 Ovrebo & Weber Verpa conica (bell morel) It is recognized by the brown, smooth to slightly wavy, bell-shaped apothecium that is attached only at the stalk apex (Fig. 6), resembling a thimble sitting on a finger. For that reason it is also called the thimble morel. Figure 6 Verpa conica Helvella acetabulum This differs in outward appearance from the previous because the apothecium is cup-shaped (Fig. 7). The inside of the apothecium is brown to grayish brown. A very short stalk may be present or absent. Its surface has sharp-edged ribs that extend onto the lower surface of the apothecium, sometimes nearly to the margin of the cup. Figure 7 Helvella acetabulum Helvella stevensii This is a relatively small fungus. The spore-bearing surface of its apothecium is ivory to pale tan at maturity. In some views mature apothecia often resemble pies with a missing wedge (Fig. 8) or have three lobes, but in young apothecia the margins are rolled over the spore-bearing surface. The undersurface of the apothecium is covered with short hairs that can be seen with a hand lens. The stalk is round in outline or slightly flattened. Figure 8 Helvella stevensii Urnula craterium (devil’s urn) The apothecium of this fungus is shaped more like a water or wine goblet than a drinking cup because of its long stalk (Fig. 9). Apothecia are dark brownish black overall and typically arise in clusters from, or adjacent to, downed logs. Urnula craterium is generally the first fungus to appear in the spring, often well in advance of the morels. Figure 9 Urnula craterium 60 Oklahoma Native Plant Record Volume 8, Number 1, December 2008 Ovrebo, C.L. Sarcoscypha occidentalis (stalked scarlet cup) This cup fungus makes its first appearance in late spring and fruits throughout the summer and into the early fall. It is a small fungus with the apothecium seldom being larger than one cm across (Fig. 10). The apothecium is bright red and the stipe is white. This fungus appears to fruit on the soil but is actually attached to buried wood. Figure 10 Sarcoscypha occidentalis