Myc. Writ. 1: 203. 1904.
Common Name: Sculpted puffball
Synonym: Lycoperdon sculptum Harkness
Fruiting body up to 14.0 cm tall, turbinate to pyriform in age, generally taller than wide, usually with a well-defined sterile base, the latter not rooted but attached to the substrate via white rhizomorphs; exoperidium white to cream, thick, upper portion of sporocarp covered with large pyramidal warts with tapered, often recurved tips; surface of warts horizontally-lined, appearing terraced; at maturity the warts breaking free at their bases, resulting in an irregular apical opening; endoperidium, membranous, thin, cream to pale-tan, falling away with the exoperidium, occasionally persistent, if so, then opening like the exoperidium; gleba at first whitish, then yellowish-olive, finally dingy yellowish-brown to olive-brown, powdery, but with some texture; subgleba occupying up to one-half of the fruiting body, whitish in youth, cellular, becoming brown to sometimes purplish-brown in age.
Spores 3.5-5.0 µm, globose to subglobose, moderately thick-walled, inconspicuously echinulate with a central oil droplet, some with a nub-like, >1.0 µm pedicel; capillitial pits common, round to slightly elongated.
Solitary or in small groups on soil and duff in conifer woods at higher elevations of the Sierra Nevada mountains; fruiting from late spring to early summer, dried specimens sometimes persisting into the fall; fairly common in most years.
Edible when young and the gleba still white, but see Comments.
A striking and beautiful puffball, Calvatia sculpta is named for the large, recurved pyramidal warts that decorate its surface. In older specimens, the distinctive hooked warts may flatten leading to confusion with Calbovista subsculpta. The latter can be differentiated by a more rounded shape, a root-like extension into the soil, and warts that have a matted-tomentose surface, not terraced as in Calvatia sculpta. Both species occur at mid to higher elevations of the Sierras and Coast Range in the spring with Calbovista subsculpta being the more common. As noted by Arora (1986), Calvatia sculpta bears a superficial resemblance to Amanita magniverrucata, a possibly toxic, white Amanita with large pyramidal cap warts that occurs along the coast. These unrelated fungi fruit at different times of year at very different elevations, thus the risk of misidentification is low. Still inexperienced collectors considering Calvatia sculpta for the table, especially in the Coast Range, should section young specimens longitudinally to rule out the possibility of an embryonic Amanita.
Desjardin, D.E., Wood, M.G. & Stevens, F.A. (2015). California Mushrooms: The Comprehensive Identification Guide. Timber Press: Portland, OR. 560 p.
Harkness, H.W. (1885). Fungi of the Pacific Coast. Bulletin of the California Academy of Sciences 1(3): 159-176. (Protologue)
Zeller, S.M. & Smith, A.H. (1964). The genus Calvatia in North America. Lloydia 27: 148-180.