Scleroderma polyrhizum

Scleroderma polyrhizum, commonly known as the star earthball or dead man's hand, is a basidiomycete fungus and a member of the genus Scleroderma, or "earthballs". Found in dry, sandy soils, this species begins completely buried before slowly forcing the soil aside as it cracks apart to form a rough, star-shaped body with a diameter of 12–15 cm (4.7–5.9 in). At the center is the dark, brownish spore mass. Widely distributed wherever the soil and climate are favorable, it is known from Asia, Europe, and the Americas.

Scleroderma polyrhizum
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Fungi
Division: Basidiomycota
Class: Agaricomycetes
Order: Boletales
Family: Sclerodermataceae
Genus: Scleroderma
S. polyrhizum
Binomial name
Scleroderma polyrhizum
(J.F.Gmel.) Pers. (1801)
  • Lycoperdon polyrhizum J.F.Gmel. (1792)
  • Scleroderma geaster Fr. (1829)
  • Sclerangium polyrhizon (J.F.Gmel.) Lév. (1848)
  • Sclerangium polyrhizum (J.F.Gmel.) Lév. (1848)



The species was first described by Johann Friedrich Gmelin in 1792 as Lycoperdon polyrhizum.[3] Christiaan Hendrik Persoon transferred the species to the genus Scleroderma in his 1801 work Synopsis methodica fungorum.[4] Elias Fries's Scleroderma geaster (published in 1829[5]) is a synonym;[1] the epithet geaster refers to the similarity with earthstar fungi of the genus Geastrum.[6] In 1848, Joseph-Henri Léveillé considered the star-shaped opening of mature fruit bodies to be a distinct characteristic and proposed the genus Sclerangium to contain the taxon.[7]

According to the classification of Scleroderma proposed by Gastón Guzmán in 1970,[8] Scleroderma polyrhizum is placed in the subgenus Sclerangium, which includes species with partially reticulate spores.[6]

Common names that have been used for the fungus include: many-rooted earthball,[9] earthstar scleroderma,[10] star earthball,[11] and dead man's hand.[12]



When unopened, the fruit body ranges in shape from round to flattened to somewhat irregular, sometimes with lobes. As the mushroom matures, the peridium (outer skin) opens in a star-like manner to form 4–8 rays that curl back and expose the inner spore mass (gleba). Typically, more than half of the fruit bodies remains buried in the ground, attached by white, string-like or flattened strands rhizomorphs. The peridium is tough and thick, typically 0.3–1 cm (0.1–0.4 in), with a rough and cracked surface. It is initially white, then turns yellowish to light brown as it matures. When unopened, the fruit body is 4–15 cm (1.6–5.9 in) wide, expanding to 12–30 cm (4.7–11.8 in) after rupturing. In young specimens, the gleba is firm and light grey, but it becomes dark brown and powdery after the spores mature. The spores are spherical, partially reticulate with warts or spines, and measure 6–11 μm.[13] A drop of dilute potassium hydroxide placed on the surface of the fruit body will either be nonreactive or turn the peridium slightly yellow.[14]

The species contains toxins which, if ingested, cause serious gastric upset.[15] It is also similar to other poisonous species.[12]

Similar species


Scleroderma texense has a fruitbody similar in appearance to S. polyrhizum. Some authors have considered them synonymous,[16] but Guzmán's 1970 study of the type showed that S. texense is distinct.[8] It typically has an exoperidium that is more yellowish or orangish, with thick, folded scales in maturity.[16] S. citrinum is also similar.[12]

Scleroderma polyrhizum
 Glebal hymenium
 No distinct cap
 Hymenium attachment is irregular or not applicable
 Lacks a stipe
   Edibility is unknown or poisonous

Habitat and distribution


Fruit bodies of Scleroderma polyrhizum grow singly, scattered, or in clusters, usually on hard clay or sandy soil, gravel, in lawns, or bare soil. Fruiting occurs in late summer and fall,[11] although blackened rays can sometimes be found in the winter.[10] It has a wide distribution in North America,[17] including Mexico.[16] It has also been recorded from Africa,[18] Asia (China[19] and Japan[20]), Europe,[21][22] South America (Brazil),[23] and Oceania.[18]

Although Scleroderma polyrhizum is probably a saprobic species,[17] experimental evidence suggests that it is also mycorrhizal. When a slurry of spores was inoculated with seedlings of Monterey pine (Pinus radiata), the fungus grew ectomycorrhizae that were dichotomously branched and formed coral-like structures comprising more than 50 branches. These structures were 1–2 mm long and 0.4–0.6 mm in diameter.[24]

The mushroom was featured on a Libyan postage stamp in 1985.[25]



Scleroderma polyrhizum fruit bodies have been used in Traditional Chinese medicine in the treatment of treatment of detumescence and hemostasis.[26] They contains the steroid compounds ergosta-4,6,8(14) 22-tetraen-3-one and 5α,8α-epidoxyergosta-6,22-dien-3β-ol as well as palmitic acid and oleic acid.[27]

See also



  1. ^ a b "Scleroderma polyrhizum (J.F. Gmel.) Pers. 1801". MycoBank. International Mycological Association. Retrieved 2012-10-01.
  2. ^ "Scleroderma polyrhizum (J.F. Gmel.) Pers". Index Fungorum. CAB International. Retrieved 2012-10-02.
  3. ^ Gmelin JF. (1792). Systema Naturae. Vol. 2 (13 ed.). Leipzig, Germany: G.E. Beer. p. 1464.
  4. ^ Persoon CH. (1801). Synopsis methodica fungorum (in Latin). Göttingen: Henricum Dieterich. p. 156.
  5. ^ Fries EM. (1829). Systema Mycologicum (in Latin). Vol. 3. Greifswald: Moritz. p. 46.
  6. ^ a b Phosri C; Martín WP; Watling R; Jeppson M; Sihanonth P. (2009). "Molecular phylogeny and re-assessment of some Scleroderma spp. (Gasteromycetes)" (PDF). Anales del Jardín Botánico de Madrid. 66S1: 83–91. doi:10.3989/ajbm.2199.
  7. ^ Léveillé JH. (1848). "Fragments Mycologiques". Annales des Sciences Naturelles Botanique. Série 3 (in French). 9: 119–44.
  8. ^ a b Guzmán G. (1970). "Monografia del género Scleroderma Pers. emend. Fr". Darwiniana (in Spanish). 16: 233–407.
  9. ^ Læssøe T; Pegler DN; Spooner B. (1995). British Puffballs, Earthstars and Stinkhorns: An Account of the British Gasteroid Fungi. Kew: Royal Botanic Gardens. p. 28. ISBN 978-0-947643-81-2.
  10. ^ a b Lincoff GH. (1989). National Audubon Society Field Guide to North American Mushrooms. New York, New York: AA Knopf. pp. 642–3. ISBN 978-0-394-51992-0.
  11. ^ a b McKnight VB; McKnight KH. (1987). A Field Guide to Mushrooms: North America. Peterson Field Guides. Boston, Massachusetts: Houghton Mifflin. p. 363. ISBN 978-0-395-91090-0.
  12. ^ a b c Davis RM; Sommer R; Menge JA. (2012). Field Guide to Mushrooms of Western North America. University of California Press. pp. 375–376. ISBN 978-0-520-95360-4.
  13. ^ Arora D. (1986). Mushrooms Demystified: A Comprehensive Guide to the Fleshy Fungi. Berkeley, California: Ten Speed Press. pp. 710–1. ISBN 978-0-89815-169-5.
  14. ^ Kuo M; Methven A. (2014). Mushroom of the Midwest. Urbana, Illinois: University of Illinois Press. p. 356. ISBN 978-0-252-07976-4.
  15. ^ Miller Jr., Orson K.; Miller, Hope H. (2006). North American Mushrooms: A Field Guide to Edible and Inedible Fungi. Guilford, CN: FalconGuides. p. 465. ISBN 978-0-7627-3109-1.
  16. ^ a b c Guzmán G; Cortés-Pérez A; Guzmán-Dávalos L; Ramírez-Guillén F; del Refugio Sánchez-Jácome M. (2013). "An emendation of Scleroderma, new records, and review of the known species in Mexico". Revista Mexicana de Biodiversidad. 84: S173–S191. doi:10.7550/rmb.31979.  
  17. ^ a b Kuo M. (February 2006). "Scleroderma polyrhizum". Retrieved 2012-10-02.
  18. ^ a b Zhishu B; Zheng G; Taihui L. (1993). The Macrofungus Flora of China's Guangdong Province. New York, New York: Columbia University Press. pp. 567–8.
  19. ^ Jian-Zong L. (2003). "Studies of Scleroderma from China". Hunan Shifan Daxue Ziran Kexue Xuebao (in Chinese). 26 (4): 60–4. ISSN 1000-2537.
  20. ^ Yoshimi S. (2002). "Taxonomic study of the Japanese taxa of Scleroderma Pers". Nippon Kingakukai Kaiho (in Japanese and English). 43 (1): 3–18. ISSN 0029-0289.
  21. ^ Calonge FD. (1980–1983). "The genus Scleroderma Gasteromycetes in Spain". Revista de Biologia (Lisbon) (in Spanish). 12 (1–2): 49–60.
  22. ^ Story M. (2009). "Earthballs – British Scleroderma species". Field Mycology. 10 (4): 122–7. doi:10.1016/S1468-1641(10)60607-X.
  23. ^ Baseia IG; Milanez AI. (2000). "Primeiro registro de Scleroderma polyrhizum Pers. (Gasteromycetes) para o Brasil" [First record of Scleroderma polyrhizum Pers. (Gasteromycetes) from Brazil]. Acta Botanica Brasilica. 14 (2): 181–4. doi:10.1590/S0102-33062000000200006.
  24. ^ Dunabeitia MK; Hormilla S; Salcedo I; Pena JI. (1996). "Ectomycorrhizae synthesized between Pinus radiata and eight fungi associated with Pinus spp". Mycologia. 88 (6): 897–908. doi:10.2307/3761052. JSTOR 3761052.
  25. ^ Moss MO. (1998). "Gasteroid Basidiomycetes on postage stamps". Mycologist. 12 (3): 104–6. doi:10.1016/S0269-915X(98)80005-0.
  26. ^ Xianling G; Rensen Z; Shiming L; Chongren Y; Qingan Z. (2005). "Chemical constituents from the fruit bodies of Scleroderma polyrhizum". Natural Product Research and Development (in Chinese). 17 (4): 431–3.
  27. ^ Gonzalez A; Bermejo-Barrera J; Toledo-Marante FJT. (1983). "The steroids and fatty acids of the basidiomycete Scleroderma polyrhizum". Phytochemistry. 22 (4): 1049–50. doi:10.1016/0031-9422(83)85062-6.