E-Flora BC: Electronic Atlas of the Flora of British Columbia

Summary:
Scleroderma citrinum differs from other Scleroderma species in having scales disposed in rosettes (with a central pyramidal wart and smaller scales arranged radially) and in the structure and size of the spores. Features include 1) spherical or somewhat flattened yellowish or yellowish brown fruitbody with scales the same color or darker, turning pinkish to dark reddish when rubbed, 2) the peridium [covering] 0.1cm thick or more when dry, and corky-rubbery in consistency, 3) the spore mass whitish and firm but soon violaceous brown or dark violaceous and finally powdery and violet-black to blackish brown, 4) attachment to soil or rotten wood by a short thick rhizomorphic stem-like base, 5) growth on soil or sometimes rotten wood, and 6) spiny reticulate spores. This is a common Scleroderma in the Pacific Northwest.

Collections were examined from ID, MI, PA, Finland, Germany, and United Kingdom, (Sims) and from OR, NS, ON, PQ, AL, CA, CT, DC, DE, FL, IA, IL, IN, LA, MA, MD, ME, MI, MO, NC, NH, NJ, NY, OH, PA, TN, TX, VA, VT, WI, WV, Mexico, Argentina, Brazil, Uruguay, Ghana, Belgium, Czech Republic, Denmark, Estonia, France, Germany, Italy, Netherlands, Portugal, Russia, Spain, Sweden, United Kingdom, China (Tibet), India, and Vietnam, (Guzman). There are collections from BC at the Pacific Forestry Centre (mostly as Scleroderma aurantium). The University of Washington has at least one collection from WA.

Outer Surface:
(2)4-8(10)cm across, spherical, when young whitish, when mature yellowish brown or yellow with scales the same color or darker, the cracks on the surface are colored orange or dark reddish, on rubbing the young surface changes dark reddish, but not brightly; smooth when young, maturing quickly with a complex cracking which forms the scales disposed in rosettes that characterize the species, the scales on mature specimens nevertheless varying from small and irregular on the base, and imbricate and triangular on the sides, to disposed in rosettes at the top, (or in some very developed fruitbodies the rosettes may cover the whole surface), the scales disposed in rosettes consist of pyramidal protuberances, surrounded radially by other smaller triangular or rectangular protuberances; peridium [covering] 0.2-0.3cm thick when fresh, 0.1cm more or less when dry, flexible, context corky, rubbery, becoming spongy and hard, whitish to yellowish, with a thin layer next to the outside that is colored like the surface or dark reddish, the peridium is in contact with the spore mass by a sinuous and poorly defined violaceous layer, pseudocolumella at times a little developed; dehiscence [opening] by irregular cracks and grooves at the top of the fruitbody, sometimes becoming star-like or somewhat star-like, when dehiscence occurs the scales separate from each other and the spaces turn yellowish orange or dark reddish, (Guzman), 3-10(15)cm across; many coarse brown scales on lemon-yellow to pale yellow or brownish yellow background, peridium up to 0.5cm thick, leathery, tough, ruptures irregularly at top to release spores, (Breitenbach), 2-10(12)cm across and 2-6cm high, spherical or somewhat flattened; yellow-brown to dingy yellow to ocher or tan; "cracked or arranged into prominent, inherent scales which often have a smaller, central wart"; peridium 0.1-0.3cm thick, hard and rind-like, white when sectioned but usually staining pinkish if fresh; "eventually cracking into lobes to form an irregular pore", the lobes not normally "bending outward or unfolding appreciably", (Arora), "sometimes pale or cream-white because the pigment is water-soluble", (Lincoff(1)), peridium less than 0.2cm thick, "covered in regular scales and cracks arranged in rosette near the top" of the fruitbody, (Sims), (3)4-8(12)cm across, profuse warty scales are dark brown over a yellow-brown background, slight cracking around scales, "apical cracking to irregular pore to open, not stellate", peridium 0.2cm thick, (Ramsey), peridium thick (more than 0.1cm thick) (Buczacki)

Spore Mass:
when young, fleshy, alveolate, and white, when mature cottony-powdery and violaceous brown or dark olivaceous, the violaceous brown color appearing from the fleshy stage; the alveolae of the immature stages are colorless and they are surrounded by white delimiting structures that become yellowish and filamentous in the powdery stage; the maturation of the gleba starts in the central zone, (Guzman), "when young whitish with a violet tint, firm, later brown to black and marbled whitish, powdery", (Breitenbach); "white when very young, soon gray to purple-gray with whitish veins often running through it, then dark purple-gray to purple-black or black and still solid and firm", eventually powdery and blackish brown, (Arora), flesh hard, not spongy like Calvatia and Lycoperdon, white when very young but soon grayish violet then blackish violet, sometimes somewhat mottled, eventually violet-black or blackish brown powder, (Ammirati), violet-black with white threads (Ramsey)

Stem:
sessile or rarely with a pseudostem, generally with a short fasciculate rhizomorphic base, when the pseudostem exists it is short and broad, solid, and generally buried in the substrate, (Guzman), almost stemless with a constricted base and branched whitish mycelial strands, (Breitenbach), underside often with a stem-like base "composed of ridges, mycelial fibers, and / or adhering debris", (Arora), attached to substrate by a thick stem-like mycelial base, (Bessette), sessile to rare pseudostem (Ramsey)

Odor:
rubbery when fresh, without odor or bread-like when mature; in dried specimens there is a characteristic odor like decomposed fish (Guzman), strong and pungent when cut open (Phillips), strong and acrid (Lincoff(1))

Taste:
rubbery when fresh, without odor or bread-like when mature (Guzman), strong and acrid (Lincoff(1)), bitter (Miller)

Microscopic:
spores (9.5)11-14(16) x (9.5)11-14(16) microns, round, including the spines, spiny and reticulate, the spines 1-2.5 microns long, robust and conic but at the same time fleeting, with maturity they fragment and can almost disappear, walls less than 1 micron thick, the reticulum is irregular and fragmented, mature spores dark yellowish brown in Melzer''s reagent and in KOH; immature spores are 6.4-9.6 microns in diameter, pear-shaped to round or irregular in form, whitish or yellowish in Melzer''s reagent and in KOH, thick-walled (walls more than 1 micron thick), with a short peduncle; basidia 4-spored, 11-25 x 6-9 microns, vesiculose-pyriform, colorless, with short sterigmata, rapidly degenerating completely; clamp connections present, (Guzman), spores 11-14 x 11-14 microns, often have a well defined reticulum, but the ornamentation seems to vary greatly between subreticulate or catenulate spores, and mildly or strongly reticulate spores, (Sims), spores 8-13 x 8-13 microns, round, strongly reticulate, (Arora), spores 9-11 x 9-11 microns excluding reticulum, round, irregularly spinose-reticulate, reticulum usually incomplete and irregular; basidia 5-10 x 3-5 microns, clavate, without basal clamp connection; hyphae of gleba 3-6 microns wide, brown, thick-walled to thin-walled, septa without clamp connections, (Breitenbach, although saying that Scleroderma bovista "also has hyphae with clamps"), spores 9-13 microns in diameter excluding ornamentation, round, spiny and with ribs forming a usually incomplete net-like patter; no capillitium, (Buczacki)