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

Summary:
{See also Earthstars Table.} Features include 1) small size, up to 3.7cm across when the outer covering of the fruitbody has expanded out into rays, 2) 4-5(8) star-like rays that are not hygroscopic, but raise the spore case as if on stilts still attached at their tips to a nest-like remnant in the ground formed from the outermost layer of the rays (i.e. fornicate), 3) hoary spore case on a short stalk, opening by a distinct cone-shaped peristome outlined by a distinct raised rim, 4) dark brown mature spore mass, and 5) round spores. Confusion has resulted because Geastrum coronatum (Schaeff.) J. Schroet. and Lycoperdon coronatum Scop. are said to be synonyms, but not Geastrum coronatum Pers. According to Bates(1), Geastrum coronatum in the sense of Lloyd(1902) and subsequent American authors and in the illustrations of G. coronatum (Schaeff.) J. Schroet. in Coker(3) is Geastrum quadrifidum as used by Pegler(4) and Bates(1). As an addendum for those particularly interested, what Smith(49) described as Geastrum coronatum Pers. (used here for a separate species) is probably also Geastrum quadrifidum Pers., and its description is included here. A.H. Smith says in Smith(4) in describing G. quadrifidum Pers. that it was generally known under the name G. coronatum in the older literature, and the Smith(4) description of G. quadrifidum Pers. corresponds more or less to the Smith(49) description as G. coronatum Pers. (see G. quadrifidum). Here is the summary of features of G. coronatum Pers. in Smith(49), corresponding instead to this species: "a very easy species to recognize because of the copious white mycelial coating of unopened fructifications, the peculiar sheen over the dark pedicellate spore sac with its basal collar, the fibrillose mouth delimited by a distinct pale circle, and the manner in which the fructification typically stands up on the points of the rays when fully expanded" (Smith(49)).

Geastrum quadrifidum was found at least in Owyhee Co. in ID, (Ramsey), in the Great Lakes area of North America, and more widely distributed, (Smith(4)), known throughout the United States, and previously reported from AZ, CA, FL, MI, NJ, NY and TZ, also reported from Canada, Caribbean, Europe, United Kingdom, Japan, Mexico, New Zealand and South America, (Bates). The University of British Columbia has BC collections by Paul Kroeger and by Heather Stirling. Another collection from BC at the University of British Columbia was collected and determined by R. Bandoni under the name Geastrum minus - Geastrum minus was originally described as a variety of G. quadrifidum, but according to Bates(1) the name was used by Cunningham to include G. quadrifidum and G. minimum.

Outer Surface:
developing underground, more or less spherical, encrusted with debris, expanded fruitbody 1.3-3.7cm across, slightly taller than wide, splitting into 4-5 non-hygroscopic rays, fornicate, rays broad, arched, with tips attached to mycelial layer that stays in or on the ground; outermost mycelial layer of rays strongly encrusting debris, cup-like, whitish on inner surface, middle fibrous layer of rays thin, outer surface whitish to cream or grayish when old, innermost pseudoparenchymatous layer of rays whitish at first, becoming brownish or gray-brown, sometimes with a pinkish tinge, often splitting when old, (Pegler), exoperidium splits star-like into 4(5) rays that are bent downward when mature, lifting the fruitbody up off the ground as if on stilts (a nest-like remnant of the outermost layer of the exoperidium is left in the ground as this happens), (Breitenbach), 0.5-3cm wide when rays expanded, ''outer wall splitting into 4-8 rays which become arched upward with the tips remaining attached to the mycelial "cup" remaining on the ground; fleshy layer avellaneous to pallid or finally wood brown, often scaling away in part at least'', (Smith(4)), 0.5-2cm across, when unexpanded more or less spherical "and covered by a dense coating of white mycelium with much debris intermingled", "outer wall splitting into 4-6(8) usually strongly recurved segments in which the mycelial layer may either become stripped off and remain as an indistinct cup beneath the fruiting body (fruiting body arched upward and remaining attached to cup only by the tips of the rays) or adhering to under surface of rays"; "fleshy layer dark avellaneous to wood brown often scaling more or less completely from fibrillose layer, central part often more persistent and forming a slight collar around base of the pedicellate spore sac", (Smith(49)), up to 2cm across opened rays, outer wall "splitting into 4-6 strongly recurved rays, from which mycelial layer may become stripped and remain as an indistinct cup below or else continue to adhere to and remain attached to mycelial cover only at the tips", outer layer of rays covered with dense coat of white mycelium and debris, fleshy inner layer of rays "often scaling more or less completely from the whitish fibrillose mid-layer which remains", (Ramsey)

Inner layer:
spore case 0.7-1.3cm across, more or less spherical to ovate, often taller than wide, surface of spore case gray-brown, "sometimes with a pinkish tinge, often covered in a fine, whitish, crystalline pruina"; peristome (mouth) "fibrillose, raised, usually distinctly delimited by a raised rim", (Pegler), spore case gray-brown to lilac-brown when young, later ocherish, brownish; peristome conic, fringed, and surrounded by sharply bounded disc-shaped halo, (Breitenbach), spore case with papery wall and surface roughened with particles giving a hoary sheen on dark ground color; mouth "distinctly fimbriate from radial fibers forming a pointed cone, mouth area outlined by a distinct groove and paler than the remainder of the case", (Smith(4)), "spore sac variable in shape from subellipsoid to ovoid or subglobose"; "membrane papyraceous, surface roughened with minute glistening particles which give it a hoary sheen, ground color dark wood brown to purplish drab"; "mouth distinctly fimbriate from radiating fibers which in older specimens converge at the edge into minute teeth, at first forming a small pointed cone, silky area of mouth outlined by a distinct groove or line and paler than remainder of fruiting body", (Smith(49)), acorn-shaped spore case dark wood brown to purplish drab; distinct cone-shaped peristome, the area of the apical pore paler than the remainder of the spore case, (Ramsey)

Spore Mass:
dark brown when mature, columella "cylindric to clavate, often inconspicuous", (Pegler), chocolate brown (Smith(4)), "dark purplish brown to chocolate at maturity", (Smith(49))

Stem:
spore case stalked (rarely with double stalk), (Pegler), spore case on a pedicel (Smith(4)), pedicel 0.1-0.2cm long "and expanding above into a ridge or acute-margined rim in the form of a narrow collar" (Smith(49))

Microscopic:
spores 4.5-5.5 microns in diameter excluding ornamentation, (5)5.5-6.3 microns including ornamentation, round, verruculose, warts irregular, 0.3-0.5 microns high; capillitial hyphae 3-6 microns wide, "yellow-brown, thick-walled, with a narrow lumen", finely tapered to subacute tips 1 micron or less wide, "walls smooth or finely encrusted", (Pegler), spores 4.5-6 microns, round, verrucose [warty], about 12 warts round the circumference, brown, some with droplets; basidia not seen, cystidia not seen; capillitium threads up to 9 microns wide, thin-walled to thick-walled, red-brown, some finely incrusted, some septa with clamp connections; hyphae of the exoperidium and endoperidium thick-walled, without septa, colorless, (Breitenbach), spores 3.5-5 x 3.5-5 microns, round; capillitial threads very thick-walled, yellowish in KOH, (Smith(4)), spores 3.5-5 microns in diameter, round, covered with colorless truncate warts which more or less gelatinize in KOH, spores dark dull brown in KOH and near sepia in iodine; capillitial threads very thick-walled (lumen of cell visible as a line), yellowish in KOH, only slightly darker in iodine, (Smith(49))

Spore Deposit:
violet-brown (Breitenbach)