History of Name:
Laccaria tortilis

Agaricus tortilis Bolton, Hist. Fung. Halifax: 41, TAB XLI, Fig. A. 1788. Omphalia tortilis (Bolton) S. F. Gray, Nat. arr. Brit. pl.: 613. 1821. Laccaria tortilis (Bolton) Cooke, Grevillea 12: 70. 1884. Clitocybe tortilis (Bolton) Saccardo, Syll. Hym. V: 198. 1887. Collybia tortilis (Bolton) Quélet, Flore Mycologique: 237. 1888. Clitocybe laccata var. tortilis (Bolton) Barla, Fl. mycol. ill.: 64. 1892.
Agaricus echinosporus Spegazzini, Anales Soc. Ci. Argentina 10: 123. 1880. Clitocybe echinospora (Spegazzini) Saccardo, Syll. Fung. 5: 198. 1887. Laccaria echinospora (Spegazzini) Singer, Ann. Mycol. 41: 17. 1943.
Clitocybe revoluta Barla, Fl. mycol. ill.: 64. 1888. [non Clitocybe revoluta Peck, Annual Rep. New York State Bot. 46: 23. 1893].
Type: Tab. XLI, fig. A in Bolton, Hist. fung. Halifax vol. 1. 1788 (lectotype fide Mueller, 1991a). Epitype: GREAT BRITAIN: Scotland, Yorkshire, Tanfield Lodge, 6 September 1969, Orton 3642 (E!, fide Mueller, 1997).

Species Synopsis:


Pileus 5-23 mm broad, strongly plicate-striate, vinaceous brown to orange brown. Lamellae pinkish flesh color to slightly vinaceous. Stipe 4-15 X 1-3.5 mm, not striate, concolorous with pileus; basal mycelium white. Basidia 2 sterigmate. Cheilocystidia lacking or very scarce and undifferentiated. Basidiospores mostly 10-15 µm diam (excluding ornamentation), globose, strongly echinulate; spines up to 4 µm long and up to 2.3 µm wide at base. Found throughout North America, not common.

Habitat and Distribution:

Scattered to gregarious, occasionally caespitose, often on bare, poorly drained soil, apparently associated with both Pinaceae and Fagaceae; cosmopolitan; not common. See Specimens Examined for the list of specimens studied.

Observations:


Laccaria tortilis can be distinguished from the rest of the small, plicate-striate Laccaria taxa by its 2-sterigmate basidia which bear large, globose basidiospores with long and broad echinulae.
It has not been possible to obtain tissue cultures or germinate the basidiospores of this taxon. Material of L. tortilis was not included in the RFLP analyses of Gardes et al. (1990, 1991a).
There has been some confusion in the literature concerning the correct name for this taxon. Agaricus tortilis is the earliest name used for this macromorphological form (Bolton, 1788). Although no holotype exists and Bolton's description did not give any micromorphological data, his color plate clearly illustrated the macromorphological traits of this taxon. I agree with the majority of modern workers (e.g., Dennis et al., 1960; Orton, 1960; Bon, 1983; Moser, 1983) who use the binomial L. tortilis for this taxon based on common usage (Korf, l982a; 1982b). Additionally, an examination of representative material from the environs of the type locality shows that Bolton probably had access to specimens that fit this micromorphological form. Rea (1922), Singer (1950a, 1952), Ballero and Contu (1989) and a few others consider A. tortilis to be a smaller basidiospored species and Singer (1943b, 1950a, 1952, 1967, 1977, 1986) used L. echinospora (Spegazzini) Singer for this taxon. Clémençon (1984) recognized both L. tortilis and L. echinospora as large basidiospored taxa. He differentiated them on echinulae length with L. tortilis having shorter echinulae than L. echinospora.
In an attempt to stabilize the application of the name, Mueller (1987) designated a neotype for L. tortilis. As discussed under L. proxima, the conflicting interpretations of this name have not been resolved by designating Bolton's illustration the lectotype. To stabilize the application of this epithet, the collection that was proposed as a neotype (Mueller 1987) is now designated an epitype (Mueller, 1997).
In North American literature, Peck (1912) and Murrill (1914)
used the name in the current sense, while Coker and Beardslee (1922) used L. tortilis for specimens with 4-sterigmate basidia and moderate-sized basidiospores.
Although not frequently collected, Laccaria tortilis occurs throughout much of the United States and Canada outside of arctic habitats. Most reports under this name from the arctic refer to collections of L. pumila (see OBSERVATIONS under L. pumila).

Macromorphology:


Pileus 5-23 mm broad, convex, becoming plane to uplifted, strongly plicate-striate, subglabrous to finely fibrillose, hygrophanous, vinaceous brown to brownish orange ("Vinaceous-Brown," "Sorghum Brown" or "Orange Rufous") fading lighter in color ("Rood's Brown" to "Vinaceous-Russet"), eventually becoming buff color; margin plane, undulate, eroded or rimose; context thin, concolorous. Lamellae sinuate to adnate, distant, broad, thick, pinkish flesh color to slightly vinaceous ("Flesh Color" to "Light Russet-Vinaceous"). Stipe 4-15 x 1-3.5 mm, equal to subbulbous, dry, finely fibrillose, not striate, concolorous with pileus. Basal mycelium white. Basidiospores white in mass.

Micromorphology:


Pileipellis of interwoven hyphae with widely scattered fascicles of ± perpendicular hyphae; fascicles composed of 5-15 hyphae; terminal cells of fascicular hyphae 26.5-69 x 6.5-15 µm, filamentous to clavate; walls up to 0.5 µm thick, light yellowish brown. Pileus trama tightly interwoven, morphologically undifferentiated, hyaline, light yellowish brown toward pileipellis. Lamellar trama parallel; hyphae mostly 6-14.5 µm diam, thin-walled, hyaline to light yellowish brown; cells barrel-shaped. Subhymenium morphologically undifferentiated. Basidia 33-64 x 7-16 µm, clavate, hyaline; sterigmata 2(-3), up to 11.5 µm long. Cheilocystidia lacking or scarce; filamentous. Basidiospores (excluding ornamentation) [90/6] (9.2-)10-14.5(-16) x (8.3-)10-14.5(-16) µm [ = 10.9-13 x 10.5 12.7 µm], Q = 1-1.09(-1.17) [ = 1-1.03(-1.07)], globose, rarely subglobose, hyaline, strongly echinulate; echinulae 1.4-3.2(-4) µm long up to 2.3 µm wide at base, crowded; hilar appendix 1.3-2.3 µm long, prominent, truncate; plage present; contents occasionally uniguttulate. Basal mycelium hyphae 3-14 µm diam, tightly interwoven, hyaline; cells filamentous to barrel-shaped.