Tulostoma volvulatum Borshchov var. volvulatum (Fig. see 150; Pls. XXIV:1-4; XLIX: 1; L: 4) - Materialy dla botanicseskoi geografii Aralo-Kaspiiskago kraia-Zapiski. Imp. Acad. Nauk St. Petersbourg 7: 189. 1865 (In Russian).
= T. boissieri Kalchbrenner, Rev. Mycol. 3: 24, tab XV, fig. 2. 1881.
= T. barbeyanum P. Henn., Bull. Herb. Boissier 1: 99. 1893.
= T. ruhmerianum P. Henn., Hedwigia 37 (6): 288. 1898.
Etym.: The name refers to the volvate structure found at the base of the stem.
Spore-sac globose to globose-depressed, up to 25 mm diam, averaging 20 mm. Exoperidium thinly membranous, rapidly deciduous, making its observation difficult in herbarium specimens or when weathered; most times it appears as a thin hyphal layer, quite indistinct, perfectly separable though from the endoperidium, sometimes outwardly agglutinated with sand particles, light-coloured, persisting at he base. Endoperidium almost white with or without pink hues, sometimes slightly ochraceous or cream-coloured, feeling chamois-like, very smooth and tough, relatively thick and only becoming papyraceous in old and empty peridia. Mouth circular, generally plane, without a rim or lip, up to 3 mm diam., rapidly becoming lacerate and most times remaining as an indefinite torn aperture, which makes identification difficult, since its circular nature soon disappears; some spore-sacs may have more than one mouth. Socket not very conspicuous, not very separated from the stem and, in some specimens, closely embracing it by means of the prominent discoid membrane of the collar which appears as a thick ring at the base. Gleba chocolate colour to very dark ferrugineous to sepia. Stem concolorous with the exoperidium or slightly darker (it may be very - Tight brown), obese, up to 70 x 9 mm, the usual size being 40-50 x 5-6 mm; woody to subwoody, rugose, rugose-squamose (particularly in the lower half), fibrous or longitudinally striate, subequal, slightly tapering towards the base, fistulose, provided at the base with a conspicuous volviform structure; in some specimens a radicating base of rhizomorphic nature may be observed.
Endoperidium formed by hyaline threads bluntly swollen at the hardly notorious septa; some specimens exhibit larger hyphae that resemble mycosclereids, but hyaline, averaging 10 Âµm diam. Spores dark brown and always smooth under L.M.; subglobose to elliptic, guttulate, thick-walled, 4.5-6.6 Âµm diam, averaging 5-5.5 Âµm diam; under SEM they also appear perfectly smooth. Capillitium coloured, generally some hue of brown, usually sepia, branched, but most threads ribbon like, with short lateral branched, walls commonly thick but lumen visible to solid, disjointable in short segments, leaving the threads with blunt, hardly at all swollen ends; septa absent or extremely rare, 2.4-9 Âµm diam. In some specimens the walls are cyanophilous!
Habitat: in sandy soils in exposed desertic or semidesertic areas, solitary.
Distribution: Africa: Mauritania, Algiers, Tunisia, Egypt, Soudan. Asia: China (Mongolia), India, Pakistan, U.S.S.R. Asia MINOR: Jordania. North America: United States (California, Colorado, New Mexico, Texas, Utah), and probably also in Mexico. Europe: probably in Spain.
Illustration: Hollos (1904: pl. 11, figs, 17, 21; pl. 29, figs. 13-14); Patouillard (1910: pl. 9, fig. 1).
Sporophore having sporocarp, stipe, volva and radicating base. Sporocarp subglobose to depressed-globose, 7-26 mm. high by 12-52 mm. wide, prominently concave at insertion of stipe, firmly attached to stem apex. Exoperidium semi-membranous, 1 mm. thick, deciduous, (Fig. 25c) often leaving some sand on the endoperidium, which finally falls off, thus becoming completely deciduous. Peridial sheath usually completely deciduous. Endoperidium white when young soon becoming light buff to cinnamon, membranous, tough, often with large circular wart-like excrescences which sometimes fall out leaving holes through to the gleba, minutely asperate or becoming smooth in age, minutely pitted around mouth in some plants. Mouth solitary, indefinite, central, naked, circular rarely with slightly raised edges from extrusion of gleba, which are friable and crumbling to enlarge the stoma to an irregular circular or oval orifice, rarely truly lacerate; only one true mouth, but a few plants may have 2-5 openings produced by wart-like excrescences on the endoperidium, dropping out, leaving holes simulating true stomata (Fig. 25b), 0-6 mm. in size, usually 2-4 mm. rarely splitting under extreme weathering. Collar from inconspicuous to prominent, margin on some irregularly fimbriate from fragments of stem cortex, rarely the upper part of volva adheres to the collar (Fig. 25d), socket usually large and strongly concave, rarely flat.
Stipe even to attenuate downward, 1-15 cm. long by 4-18 mm. thick, apex dilated, usually straight, rarely curved or tortuose (Fig. 25a), smooth when first emerged, the outer cortical layer caducous, often in large flakes or scales, thereby exposing the next layer which is white when fresh but soon becomes pinkish buff to cinnamon, hard, striate to strongly sulcate, woody, walls thick, lumen small having a prominent white mycelial strand. Volva very large, firm, cup-shaped, 10-25 mm. wide by 8-10 mm. high, covered with sand, persistent, context dingy white, base of stem inside volva slightly enlarged. Base radicating, roots central, stout, 6-12 mm. thick, several cm. long, usually only 4-10 mm. long in herbarium specimens. Gleba Kaiser brown to hazel. Capillitium colored, branched, septa very rare, slightly swollen. Spores globose to ellipsoid, 3.7-5.2 Âµm in diameter. Epispore hyaline to slightly yellowish, medium thick, smooth.
Habitat: SoIitary, usually in deep sand.
One specimen in Ahmad collection no. 301 measured as follows: peridium 3.4 cm. in diameter, 2 cm. high, mouth a torn aperture 8 mm. wide, stipe 14 cm. long, 1.3 cm. thick at apex and 8 mm. thick at base, volva 2.2 cm. in diameter. Abmad collection no. 302 had many small plants, some only 1.3 cm. in diameter by 6 mm. high and stipe 26 mm. long by 9 mm. thick; this was due to long dry periods in which the plants did not reach their normal sizes.