Pseudoinonotus dryadeus

What You Should Know

Inonotus dryadeus, (syn. Pseudoinonotus dryadaeus) is an inedible species of fungus belonging to the genus Inonotus, which consists of bracket fungi with fibrous flesh. Most often found growing at the base of oak trees, it causes white rot and decay of the trunks. It secretes an amber liquid that weeps from tubes in its upper surface.

The thick fruiting body of Inonotus dryadeus varies in size from 5 cm to 30 cm in width, although specimens up to 75 cm have been found. Its velvety upper surface is cream to rusty brown with a yellower margin, and is pitted with tubes up to 3 cm deep which ooze an orange-brown liquid when the fruit body is young, hence the name "weeping conk".

On the buff underside there are 4–6 fine pores per millimetre. These are initially grayish-white but mature to yellow or ochre.

The flesh is soft and fibrous, yellow-brown, and has an unpleasant odor.

Other names: Oak Bracket, Warted Oak Polypore, Weeping Polypore, Weeping Conk.

Pseudoinonotus dryadeus Mushroom Identification

1. Cap

   Up to 40cm across and typically 10 to 15cm thick, the orange-brown brackets of Pseudoinonotus dryadeus become irregularly shaped as the fruitbody matures. Occasionally they occur in tiers of three or more brackets. As the infection increases, fruitbodies can occur on roots some distance away from the trunk of the tree.

   The cap flesh is felty or even slightly hairy at first and becomes harder and more uneven with age. Drops of an amber 'runny honey' liquid ooze from a paler 'set honey' background to create a most attractive patterned surface. Unfortunately, the similarity with honey does not extend to the taste.

2. Tubes and Pores

   The grayish tubes of the Oak Bracket, spaced at 4 to 6 per mm, also exude a thick amber liquid when young.

3. Spores

   Broadly ellipsoidal, smooth, 7.5-8.5 x 5.5-6.5μm.

4. Spore Print

   White.

5. Odor and Taste

   The smell of old fruitbodies is strongly unpleasant; the taste is slightly acidic but not distinctive.

6. Habitat & Ecological Role

   Oak Bracket occurs at or near the base of living and dead broad-leaf trees, nearly always oaks but occasionally beech and other hardwoods; it causes white rot.

7. Similar Species

   Fistulina hepatica, the Beefsteak Fungus, is soft and oozes red juice when cut.

Pseudoinonotus dryadeus Taxonomy and Etymology

Described scientifically in 1799 by Christiaan Hendrik Persoon, who established the basionym of this species when he gave it the binomial scientific name Boletus dryadeus, the Oak Bracket's currently-accepted scientific name dates from a 2001 publication by German mycologists Tobias Wagner and Michael Fischer. Before 2001 this species was recorded in field guides as Inonotus dryadeus.

Synonyms of Pseudoinonotus dryadeus include Boletus dryadeus Pers., Polyporus dryadeus (Pers.) Fr., and Inonotus dryadeus (Pers.) Murrill.

Pseudoinonotus dryadeus is the type species of the genus Pseudoinonotus, which was circumscribed by Tobias Wagner and Michael Fischer in 2001.

The generic name Pseudoinonotus is made up of Pseudo- meaning false, easily confused with, or masquerading as, ino- meaning fibrous, and ot, which means an ear (the -us extension is there merely to make it into a Latinised noun. This suggests that species in the Pseudoinonotus genus look rather like Inonotus fungi, which are fibrous and ear-like.

The specific epithet is much easier: dryad means oak, and the suffix -eus means belonging to or pertaining to; so, fungi with dryadeus as part of their scientific name are found with or on oaks. Some people refer to this as the Weeping Polypore, which seems quite apt until you realise that other brackets in the genus Inonotus also weep - for example, see Inonotus radiatus.

Sources:

Photo 1 - Author: Lukas from London, England (Creative Commons Attribution-Share Alike 2.0 Generic)

Photo 2 - Author: Brammers (Public Domain)

Photo 3 - Author: Liz Popich (Lizzie) (Creative Commons Attribution-Share Alike 3.0 Unported)

Photo 4 - Author: Lukas from London, England (Creative Commons Attribution-Share Alike 2.0 Generic)