Midwest

American

Mycological

Information

Laetiporus sulphureus
Laetiporus cincinnatus

L sulphureous

L sulphureous

L cincinnatus

L cincinnatus

Common name: Chicken of the Woods, Sulfur Shelf.

Description and identifying characteristics: An orange, shelf mushroom that grows individually or in large brackets from the vertical face of a log or living tree, or in circular florets arising from the top surface of a log, base of a tree, or piece of buried wood/root. They are commonly found on wounds of trees. They occur frequently on oak, although they can also be found on maple, chestnut, willow and other hardwoods.

Fruiting bodies are comprised of one to several laterally-stiped caps arranged in an overlapping, shelf-like formation. Individual mushrooms range from 5–30 cm (2-12 inches) across, while whole brackets or florets of mushrooms can measure up to 60 cm (24 inches) across or larger. Larger specimens can weigh up to 26 kg (50 pounds) or heavier.

Mature, ripe and choice fruiting bodies are characterized by a moist, firm, spongy texture, yellow to orange color, with bright orange or yellow tips. Older, dry, over-ripe brackets become pale and brittle, having a chalk-like consistency.

Laetiporus mushrooms are polypores, meaning they have pores on the underside of their caps rather than gills. The hymenium (spore-bearing surface) lines the insides of the pores, which may be up to 5 mm deep. Although the spores and spore-prints of all Laetiporus species are white, the pores and underside of the cap of L. sulphureus is yellow. L. cincinnatus has a white-colored pore surface and undercap. Microscopically, the spores are smooth elliptical to ovoid, and 5.5-7 x 3.5-5 microns in dimension.

There are some Laetiporus species that grow on conifers, but to the best of this author’s knowledge, these have not been found to occur in the Midwestern United States.

Ecology/associates host or habitat: Laetiporus species are a type of brown-rotting fungi, which produce a reddish-brown cubical rot and embrittlement of wood. This weakens living trees infected with Laetiporus species, and may cause the host tree to be prone to wind-fall. Laetiporus species can be either parasitic on live (or dying) trees, or saprophytic on logs, stumps or buried roots/wood. In Midwest America, they occur May–November.

Laetiporus are mainly found in hardwood forests, but it is not unusual to see them fruiting on trees or stumps in rural environments. Harvesting mushrooms for consumption in rural environments, however, is discouraged, as fungi can absorb pesticides and other chemicals from the environment and concentrate them in their fruiting bodies.

Poisonous Look-alikes: There are no reasonable look-alikes to this fungus. Another large, orange, mushroom is the Jack-O-Lantern fungus, Omphalotus olearius. Jack-O-Lanterns, however, have gills rather than pores, and are easily distinguished based solely on that characteristic.

Tips on harvesting/storage: Brackets and rosettes may be harvested whole. Individual mushrooms are best harvested by cutting stems one-half inch above where 1) they attach to the log or substrate, 2) there is any visible dirt or detritus on the mushroom. Specimens should be cleaned by gently brushing away any dirt or detritus with a mushroom brush.

Brackets and rosettes can also be harvested in a sustainable manner by removing the more delectable and desirable tips of each mushroom and leaving the main body intact. Regrowth of the tips can occur in as short as two-three weeks. Below the tips, Laetiporus mushrooms can get progressively corky as you move away from the tip, especially in older specimens. By slicing a sharp knife into a Laetiporus mushroom at an angle perpendicular to the tip of the cap, you can determine the point at which the mushroom starts to get corky due to increased resistance to the cut. With experience, you’ll be able to determine the proper depth of harvesting the tips in order to maximize yield and sustainability.

If a Laetiporus mushroom is discovered to fruiting on particular tree or log, that tree or log will likely continue to produce more Laetiporus mushrooms, possibly for years. Be sure to note the GPS coordinates of the tree for future harvests.

Possible allergic reactions and symptoms: Sulphur-shelf fungi are considered choice and edible by most people. As with other mushrooms and foods, however, some individuals have demonstrated a specific allergy to sulphur-shelves, which manifests itself as a gastrointestinal distress.

It has been reported that Laetiporus species growing on conifers (e.g. L. conifericola) can cause severe allergic reactions (see Bueg in the references, below). As such, although Laetiporus mushrooms have never been reported growing on conifers in Michigan (although they are commonly found growing on conifers in the western part of the U.S.), any Laetiporus mushrooms found growing on conifers should be avoided.

As a general rule, to minimize the risk of allergic reactions, it is imperative that all mushrooms, including sulphur-shelves, be cooked before consuming. It is recommended to limit your portion size whenever eating a species you’ve never eaten before. It is also advisable not to consume more than one new species of mushroom at the same time.

Special considerations for storage: As with other mushrooms, the storage of mushrooms is best in containers that allow some gas exchange rather than containers do not. In other words, mushrooms are better stored in paper bags than plastic ones. Do not store this or any other mushroom in an airtight, Ziploc-type bag.

Photos:

primodial l. sulphureous
primodial l. sulphureous

Primodial stage of L. sulphureus emerging from logs.

Sulfur-shelf
Mature sulfur-shel

Mature sulfur-shelf mushrooms

l. sulphureous
l. sulphureous

Yellow and white pore surfaces of
L. sulphureous (left) and L. cincinnatus (right)

References:
Kuo, Michael (March 2005). Laetiporus sulphureus: The Chicken of the Woods.

Lindner DL, Banik MT. (2008). Molecular phylogeny of Laetiporus and other brown rot polypore genera in North America. Mycologia 100 (3): 417–30.

Michigan Mushroom Hunter’s Club. October 2009 Mushroom of the Month.

Missouri Department of Conservation web-site.

Smith Weber, Nancy (1980). The Mushroom Hunter's Field Guide. University of Michigan Press. p. 64.

Tom Volk's Fungus of the Month for July 2001.

Roger’s Mushrooms (lots of more photos):

Michael W. Beug. Poisonous and hallucinogenic mushrooms.