Xylaria polymorpha (Dead Man's Fingers)

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by Michael Kuo

Commonly called "Dead Man's Fingers," this odd mushroom dons a variety of costumes in its rather long life span. When young (see the second illustration) it is pale with a whitish tip. The pale covering is actually a coating of asexual spores. Morel hunters frequently encounter Xylaria polymorpha in this form, in early spring. Soon, however, it begins to blacken (see the third illustration), and by fall it is entirely black and dried out (top illustration). Somewhere in the middle of this progressive costume change, Xylaria polymorpha does indeed look like a creepy set of "dead man's fingers." By the final stages, however, one is more likely to mistake it for something, um, left by a house cat.

Xylaria polymorpha is actually a cluster of hard-to-separate species that are imperfectly documented; Tom Volk (link below) estimates there are five to ten species involved.

I have no information on the edibility of Xylaria polymorpha, but it is too tough (and disgusting!) to consider eating, anyway.

Description:

Ecology: Saprobic on decaying hardwood stumps and logs; sometimes appearing terrestrial but actually attached to buried wood; growing alone or, more commonly in clusters; appearing in spring and not decaying until late summer or fall.

Fruiting Body: 2-8 cm tall; .5-3 cm across; tough; shaped more or less like a club or a finger; with a rounded tip; at first coated with a pale spore dust, but soon blackish with a pale tip; eventually black overall; surface rough or minutely pimpled.

Flesh: White; very tough.

Microscopic Features: Spores 20-32 x 5-10 µ; smooth; spindle shaped. Asexual spores (coating the fruiting body when young) smaller. Asci in perithecia, embedded in the white flesh just beneath the outer surface.

REFERENCES: (Persoon ex Mérat) Greville. (Smith, Smith & Weber, 1981; Arora, 1986; Phillips, 1991/2005; Lincoff, 1992; Volk, 2000; Roody, 2003.) Herb. Kuo 05010302.

Further Online Information:

Xylaria polymorpha at Tom Volk's Fungi
Xylaria polymorpha at Fungi of Poland

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Cite this page as:

Kuo, M. (2003, September). Xylaria polymorpha (dead man's fingers). Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/xylaria_polymorpha.html