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Stinkhorns: The Phallaceae and Clathraceae  

[ Basidiomycetes > Phallales . . . ]

by Michael Kuo

Stinkhorns are amazing mushrooms, notorious for popping up suddenly and unexpectedly in urban settings. They are very diverse in appearance, but all of them share at least two features:

  • Some part of the fruiting body, at some stage in development, is covered with a foul-smelling slime.

  • The fruiting body arises from an "egg," traces of which may disappear by maturity.

    Beyond these shared features, however, just about anything goes, and stinkhorns range from looking rather like Morels to appearing like, um, a portion of canine anatomy, or odd marine creatures with tentacles, or crab claws, Wiffle balls, Chinese lanterns, and so on.

    Stinkhorns occur "naturally" in North America, especially in subtropical and tropical regions--but some stinkhorn fruitings in temperate and north-temperate climates may be caused by human endeavors, resulting from the transportation of soil, sod, wood chips, trees, and so on. Thus MushroomExpert contributor Ron Meyers found Lysurus mokusin outside a library in Lawrence, Kansas, and contributor Tim Geho found Aseröe rubra in South Carolina.

    The method the stinkhorns use to disperse spores is quite ingenious, though a little disgusting to human sensibilities. The foul-smelling slime is calculated to attract flies and other insects, who land on the slime and gobble it up. Little do the insects know that they have been duped into covering their little insect feet with stinkhorn spores, and have ingested spores into their digestive tracts! Later, these spores are dispersed by the unwitting insects, and the stinkhorn life-cycle continues elsewhere.

    One stinkhorn, Phallus impudicus, is often mistaken for a yellow morel by summer morel hunters who are hunting with their hearts instead of their minds. However, the season alone (to say nothing of the presence of stinky slime and the underground "egg") should serve to separate the stinkhorn; morels don't grow in summer . . . and "de Nile" is not just a river in Egypt.

    In some parts of the world--not my part, mind you--stinkhorn eggs are considered delicacies, and are eaten with relish (the emotional kind). To my knowledge, no stinkhorn is known to be poisonous--and I have heard from several morel hunters who actually cooked and enjoyed mature stinkhorns, thinking they were July morels. But I do not recommend you eat them--mostly because the idea seems too disgusting, but also because, given the spore-dispersal strategy outlined above, a mature, slime-covered stinkhorn may be unsanitary. A further consideration may be the various chemicals often associated with urban soil and woodchips.

    I doubt that any mushrooms, with the possible exception of Leucocoprinus birnbaumii (which pops up out of nowhere in people's flower pots), generate more e-mails to MushroomExpert.Com than the stinkhorns. They are truly astonishing when they grow literally overnight in your yard or garden. So, to anticipate a few questions in advance: No, they won't hurt you (or your children, or your pets); No, I will not tell you how to get rid of them (it's pretty much impossible, but even if they were easily eradicated, why would a mushroom lover tell people how to kill mushrooms?); and Yes, I would love to see your photos (my e-mail address is on this page).
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    Phallus impudicus
    Phallus hadriani

    Aseroe rubra
    Aseröe rubra

    Lysurus mokusin
    Lysurus mokusin

    Mutinus elegans
    Mutinus caninus

    Traditionally, two families of stinkhorns were recognized. The Phallaceae held stinkhorns with unbranched stems, including species of Mutinus, Phallus, and Dictyophora (now synonymized with Phallus), among others. The Clathraceae included stinkhorns with branched stems and those with funky, latticed structures--including Clathrus, Lysurus, Colus, Laterna, and others. Although the current Dictionary of the Fungi contradicts itself on the status of these two stinkhorn families (the entry for the order Phallales includes the Phallaceae but not the Clathraceae, while the entry for the Clathraceae indicates it belongs in the Phallales) it is rather a moot point, since recent DNA research has indicated that the order Phallales also includes many coral mushrooms, species of Gomphus like Gomphus floccosus, and earthstars like Geastrum saccatum. See the page for the Phallales for further information.

    Be sure to check out the Stinkhorn Hall of Fame, which features stinkhorn photos sent in by our readers.


    Key to 25+ North American Stinkhorns  

    Note: Some species from Central America have been included on the assumption that they may range into tropical and subtropical regions of North America. A few African and Asian stinkhorns are treated at the site, but not in the key below. They include Colus hirudinosus, Ileodictyon cibarium, and Lysurus corallocephalus.


    1.Spore slime occurring on a ring (reminiscent of a napkin ring) near the top of a white stinkhorn with Swiss-cheese-like holes; subtropical to tropical.

    1.Not as above.
    2


    2.Spore slime occurring near the top of an unbranched structure (a stem that does not split into separate arms or columns), on the outer surface.
    3

    2.Spore slime occurring on the inner (rarely on the outer) surfaces of a branched, latticed, or columned structure which may or may not sit on top of a stem.
    12


    3.Without a clearly distinct "head" or "cap" to bear the spore slime--the stem merely covered with slime near the top.
    4

    3.With a distinct "head" or "cap" to bear the spore slime.
    7


    4.Mature stem orange or reddish orange.
    5

    4.Mature stem rose pink (without orange shades), or white.
    6


    5.Spore slime covering only 2-3 cm, the tip of the stem abruptly rounded; spores 3.5-5 x 1.5-2 µ.

    5.Spore slime covering more than 2-3 cm, the stem gracefully tapering to a point; spores 4-7 x 2-3 µ.


    6.Mature stem white (all the way to the apex, under the slime); originally described from Oregon, recorded from Michigan (range undetermined).
    Mutinus caninus var. albus
    see Mutinus elegans

    6.Mature stem dark rose pink above, rose pink to whitish below; rather stocky; stem surface with large pits; common in northeastern North America.


    7.Mature stinkhorn with a netted "skirt" (reminiscent of a doily on your grandmother's coffee table) hanging from the cap.
    8

    7.Mature stinkhorn lacking a "skirt."
    9


    8.Skirt 3-6 cm long, not extending to the ground; fairly common in eastern North America.

    8.Skirt longer than above, often extending nearly to the ground; likely to occur only in tropical and subtropical locations or in greenhouses.


    9.Mature stinkhorn with a skinny, red to scarlet or orange stem.

    9.Mature stinkhorn with a fairly thick whitish, yellowish, or pinkish stem.
    10


    10.Cap smooth or finely granular beneath the spore slime; found east of the Rocky Mountains.

    10.Cap pitted and ridged beneath the spore slime; eastern or western in distribution.
    11


    11.Egg and volva whitish to yellowish.

    11.Egg and volva pinkish to purplish.


    12.With a more or less central, single (not composite) stem that is clearly visible above the volva for at least a few centimeters; the stem may then split into columns or tentacles (which may or may not rejoin at the very top), or it may support a latticed structure.
    13

    12.Central stem if present composite, composed of multiple arms fused together--or stem absent or rudimentary, not extending more than a centimeter above the volva.
    19


    13.Stem with four to six well defined sides.

    13.Stem more or less round in cross-section.
    14


    14.Stem holding aloft a cross-latticed ball.

    14.Stem holding aloft a pointed structure that lacks prominent cross-lattices--or stem branching into vertical arms, appearing like claws or tentacles, that may fold back by maturity.
    15


    15.Stem holding aloft a pointed structure with 4-6 short columns (under 4 cm long) that are firmly fused at their tips at first but may separate slightly at maturity.
    16

    15.Stem terminating with 3-22 long arms (longer than 4 cm) that may or may not be joined at their tips initially, but by maturity may be separated and spread out like octopus or squid tentacles.
    17


    16.Claws covered with spore slime all the way to their bases, almost always separating and folding back somewhat by maturity; reported from Ohio and Kansas, and to be expected throughout subtropical and tropical North America.

    16.Claws covered with spore slime except at their bases, rarely separating or folding back at maturity; reported from the Caribbean.
    Lysurus gardneri
    at Basidiomycetes of the Greater Antilles


    17.Arms or tentacles thin, numbering 5-22, never connected at the top; spore slime covering the disc between the tentacles, or the bases of the tentacles (or both), but not extending to their tips.

    17.Arms or tentacles fairly thick, numbering 3-7, initially connected at the top; spore slime covering inner/upper surfaces of arms, all the way to their tips.
    18


    18.Arms numbering 4-7, usually separating and peeling back almost to the ground by maturity; documented from California; spores 4-7.5 x 2-2.5 µ.

    18.Arms numbering 3-4, usually remaining fused at their tips or peeling back only slightly by maturity; documented from northeastern North America and Kansas, to be expected across the continent; spores 3.5-4.5 x 1.5-2 µ.


    19.Stinkhorn consisting of a cage-like structure, with horizontal cross-lattices (at least near the top of the structure) in addition to vertical lattices.
    20

    19.Stinkhorn without horizontal cross-lattices, consisting only of vertical columns which may or may not be fused at their tips--and which may or may not peel back at maturity to appear like the arms of an octopus or squid.
    24


    20.Cross-lattices numerous, but only occurring at the top of the stinkhorn, held aloft by 4-6 vertical columns which are often fused together into a stemlike structure; reported from Jamaica.

    20.Cross-lattices not restricted to the top of the stinkhorn; variously distributed.
    21


    21.Cross-lattices rare, only occasionally occurring between 2-5 thick, vertical columns that are fused at their tips.

    21.Cross-lattices frequent, creating a cage-like appearance.
    22


    22.Growing in Florida and along the Gulf Coast; holes in the cage surrounded by "coronas" (see the photos on the page linked to the right); spores about 4 µ long.

    22.Growing on the West Coast, or in Mexico, or in the Caribbean; holes lacking coronas; spores 4-6 µ long.
    23


    23.Stinkhorn a red to orangish cage-like structure; growing in California (especially in the Bay Area) and Mexico.

    23.Stinkhorn a bright yellow cage-like structure; documented in Cuba and Jamaica.
    Clathrus baumii


    24.Spore slime borne only on a structure (a "glebifer") that hangs at the top of the stinkhorn, under the arches formed by vertical columns which are fused at their tips.
    25

    24.Spore slime not limited to an apical glebifer.
    26


    25.Columns crested longitudinally with ravioli-like edges (somewhat reminiscent of the edges that often form on Gyromitra brunnea).
    Laterna pusilla

    25.Columns simple, not crested.
    Laterna triscapa


    26.Columns white, with spore slime structures ("glebifers") lining their interior sides; documented from the Caribbean and Texas.
    Blumenavia angolensis

    26.Columns not completely white, lacking glebifers; variously distributed.
    27


    27.Spore slime confined to the upper portion of the interior surfaces of the columns (rarely lower than the top half).
    28

    27.Spore slime covering the entire interior surfaces of the columns, from top to bottom.
    29


    28.Stinkhorn with 2-5 columns up to 15 cm tall; reddish to orangish; occasionally with a cross-lattice or two; recorded from the Carolinas and the Gulf States and reported from New York.

    28.Stinkhorn with 2 columns up to 9 cm tall; orangish or yellowish; without cross-lattices; recorded from California.
    Clathrus bicolumnatus


    29.Arms numbering 4-7, usually separating and peeling back almost to the ground by maturity; documented from California; spores 4-7.5 x 2-2.5 µ.

    29.Arms numbering 3-4, usually remaining fused at their tips or peeling back only slightly by maturity; documented from northeastern North America and Kansas, to be expected across the continent; spores 3.5-4.5 x 1.5-2 µ.




    References

    Arora, D. & Burk, W. (1982). Clathrus archeri, a stinkhorn new to North America. Mycologia 74: 501-504.

    Arora, D. (1986). Mushrooms demystified: A comprehensive guide to the fleshy fungi. Berkeley: Ten Speed Press. 959 pp.

    Blanton, R. L. & Burk, W. (1980). Notes on Pseudocolus fusiformis. Mycotaxon 12: 225-234.

    Burk, W. R. (1979). Clathrus ruber in California and worldwide distributional records. Mycotaxon 8: 463-468.

    Coker, W. C. & J. N. Couch (1928). The Gasteromycetes of the eastern United States and Canada. North Carolina: University of North Carolina Press (Dover reprint, 1974).

    Dring, D. M. (1964). Gasteromycetes of West Tropical Africa. Mycological Papers 98: 1-59.

    Dring, D. M. (1980). Contributions toward a rational arrangement of the Clathraceae. Kew Bulletin 35: 1-96.

    Guzman, G., L. Montoya & V. M. Bandala (1990). Las especies y formas de Dictyophora (Fungi, Basidiomycetes, Phallales) en Mexico y observaciones sobre su distribucion en america latina. Acta Botanica Mexicana 9: 1-11. This paper is available online here.

    Kirk, P.M. et al., eds. (2001). Ainsworth & Bisby's dictionary of the fungi. Oxford: CAB International. 655 pp.

    Long, W. H. (1907). The Phalloideae of Texas. Journal of Mycology 13: 102-114.

    Metzler, S. & Metzler, V. (1992). Texas mushrooms. Japan: U Texas P. 350 pp.

    Rea, P. M. (1955) The genus Lysurus. Papers of the Michigan Academy of Science 40: 49-66.

    Smith, A. H., Smith, H. V. & Weber, N. S. (1981). How to know the non-gilled mushrooms. Dubuque, Iowa: Wm. C. Brown. 324 pp.

    Zeller, S. M. (1944). A white variety of Mutinus caninus. Mycologia 36: 263-265.



    Cite this page as:

    Kuo, M. (2007, March). Stinkhorns: Phallaceae and Clathraceae. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/phallaceae.html

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