Reishi Mushroom Identification, Species, and Foraging

Reishi Mushroom Identification Characteristics

These are the basic characteristics for identifying any type of reishi. Further down, the species is broken up so showcase the differences in types.

Ecology:

All reishi fungi are saprotrophic, meaning they feed on dead organic matter. Look for them on dead or dying trees and old stumps or logs.

The different species are particular about their host tree. Species that prefer hardwoods rarely cross the line to conifers and vice versa. Some types even limit themselves to just one or two tree types within the hardwood or conifer families.

Habitat:

Reishi only grows on wood, stumps, and logs. The tsugae species seems to prefer conifers, mainly hemlocks (tsuga means hemlock). Other species are found on hardwoods.

You won’t find this polypore growing on the ground or in fields. It is always attached to some type of wood, most often a dead stump or fallen log.

Cap:

The caps of reishi mushrooms are kidney or fan-shaped. Their coloring is reddish with a wet, lacquered appearance when young. The shiny, red-brown cap is one of the main identifying features of this mushroom.

When young, the growths are soft and oddly shaped — they aren’t at full fan-shape until they are at least a few weeks old. Young reishi look like knobs or ladles with long handles.

Much of their growth shape is determined by where they are growing. Reishi growing on the side of a tree grow outwards, horizontally. Specimens fruiting on logs often develop stems that arch to allow them to then grow horizontally.

Reishi caps rarely get larger than a foot across and an inch or two thick. They may or may not be attached to a stem. They may also start out with what looks like a stem, but as they spread out, the cap encompasses the entire specimen eliminating any supposed stem.

Many guides indicate the stem or lack of stem is a great identification feature. However, this isn’t always reliable. Stem growth, more often than not, varies based on where on the tree or log the specimen is growing. Even species that “don’t have stems” may develop them to increase the fungus’s access to sunlight and water. Or they may not grow one because they have full access to sunlight in the form it first appears.

As they age, their flesh becomes tough and the spores drop. Air currents often blow these spores to the top of the mushroom, dulling its shiny cap.

A key difference between species that can help with their identification is the color of their flesh when dried. The color ranges from white to tan to dark brown. The flesh may also have concentric textural zoning that is apparent when it is sliced.

Reproduction:

Spores come out of tiny pores on the underside of the mushroom rather than gills. This is why they’re known as polypores (poly means “many”).

Spore print:

Brown.

Time of year:

Spring to fall for all species.

Reishi season doesn’t work the same as with gilled or bolete mushrooms. They appear at a particular time of year but will remain there all year long unless harvested, eaten by slugs, or seriously decayed. The most common scenario is that they remain on the wood surface until they deteriorate so completely they fall off the tree.

It’s normal to find them dead on the ground around a stump or log or just about to fall off. This process usually takes a year but may be shorter or longer depending on the region, season, and amount of bug/slug damage.

Ganoderma oregonense

As the common name suggests, this species is found in Oregon. It’s also common all over the Pacific Northwest and in California. It grows with conifer trees and is the only known species in this region with a lacquered red cap surface growing from conifers. This reishi grows quite large and is hard to miss.

• Region: Pacific Northwest and California
• Season: Fall through spring
• Habitat: Conifers (dead or living, often injured trees)
• Size: 4-20 inches across, 2-6 inches in depth
• Shape: Semi-circle
• Cap Color: Reddish-brown, lacquered or dull with age
• Pore Color: White to pale brown, gets darker with age
• Flesh Coloring: White or cream colored, no concentric zoning
• Notes: Pore flesh bruises dark brown. The stem is usually absent.

Eastern

Ganoderma tsugae

This eastern species is stunning in youth – highly varnished to the point it looks like someone went out in the woods and gave it a thorough polish.

• Region: Northeast, Midwest, Appalachians (wherever eastern hemlocks grow)
• Season: Spring through fall
• Habitat: Eastern hemlock almost exclusively
• Size: 1.5-6.5 inches across,
• Shape: Knobby and irregular in youth, kidney-shaped with maturity
• Cap Color: Shiny, varnished burgundy-brown cap, very dark red with age, may become dull and brown. Very young specimens have white and yellow at the edges before fully forming.
• Pore Color: White to dingy brown, darkens with age.
• Flesh Coloring: White or cream colored, with concentric textural zoning
• Notes: Pore surface bruises brown. It usually has a stem, but not always.

Ganoderma curtisii

Previously, this was thought to be a southeastern species, but now it is known to be more widespread across the eastern United States. This species looks much like G. tsugae, except it grows on hardwoods. It is also easy to confuse with G. sessile.

• Region: east of the Rocky Mountains
• Season: Spring through fall, will hang on until winter
• Habitat: Hardwood logs and stumps as well as wounds on living trees
• Size: 1-5 inches across, .75-3 inches deep
• Shape: Semi-circle, fan-shaped
• Cap Color: Bright lacquered reddish-brown in maturity, often with orangish-brown zonal coloring at the edge. It starts out with concentric yellow, white and red zones until it reaches full maturity.
• Pore Color: White to tan, darkens with age.
• Flesh Coloring: Tan with no concentric zonal coloring
• Notes: Pores bruise dark brown. It usually has a long stem.

Ganoderma curtisii meredithiae/ Ganoderma meridithiae

Same as G. curtisii above, except it grows on pine trees and only appears in the southeast. It was previously thought to be a separate species, but DNA analysis put it in the same family as G. curtisii. It is the same size as its cousin, with the same coloring and growth habits.

Ganoderma sessile

This species is very similar to G. curtisii – it grows from the same type of trees, generally looks the same, and can be virtually indistinguishable except with DNA analysis. The main supposed difference is G. curtisii usually has a long stem, and G. sessile is stem-less (sessile actually means “without a stem”). However, as previously discussed, this mushroom doesn’t always follow patterns with stem growth.

Instead, the slightly more reliable way to tell them apart is through the flesh appearance. G. sessile flesh features concentric zonal coloring, while G. curtisii does not.

G. sessile also tends to look like it is growing from the ground. In reality, it is attached to seriously decayed wood, buried wood, or wood chips — it is not growing from the ground as in growing from the soil. But, it does appear on the ground.

• Region: east of the Rocky Mountains
• Season: Spring through fall
• Habitat: Hardwood trees, living, dying, or injured
• Size: 3.5-6.5 inches across, 1.5-3.5 inches deep
• Shape: Kidney-shaped or irregular semi-circle
• Cap Color: Deep reddish-brown, shiny, and lacquered appearance. Zonal coloring is common, usually tan, orangish-brown, and yellowish-brown.
• Pore Color: White, cream, or tan, darkens with age.
• Flesh Coloring: Tan or light brown with concentric zonal coloring
• Notes: Pore surface bruises dark brown. The stem is usually absent.

Reishi Lookalikes

Fortunately, there are no poisonous reishi look-alikes. In fact, there are no known poisonous polypores! So hunting for reishi is pretty safe.

Red-Belted Polypore (Fomitopsis pinicola complex)

This tree fungus also has a reddish-brown lacquered cap and grows on conifer trees, which means it is commonly mistaken for a reishi species. The primary difference is in the name — this mushroom cap has bands or belts of color.

The cap is smooth with orange-yellow coloring and a white margin in youth, then turns dark reddish to brown with an orange margin. The belts are sometimes the same color but they form distinct bands on the cap. Underneath the cap, the pore surface is yellowish or brown, another difference from reishi. This polypore also never has a stem.

The red-belted polypore is also very large, dense, and woody. When you cut it open (if you can!), the flesh does not have concentric coloring and it not pliable. It is often completely dried out. The flesh of this fungus makes an excellent fire-starter!

In 2019, the Fomitopsis pinicola species was split into 3 distinct species. Previously it was thought all occurrences of the red-belted polypore were the same. DNA analysis made clear that F. pinicola is a European and Asian species and does not occur in North America. And, North America actually has two distinct species, divided by the Rocky Mountains.

Fomitopsis mounceae occurs in the northern United States and Canada. It grows primarily with aspens and conifers. Fomitopsis schrenkii is a southwestern species that grows on conifers.