Laccaria laccata var. striatula

 

History of Name:
Laccaria laccata var. striatula

Peck, Annual Rep. New York State Bot. 48: 244. 1894. Laccaria striatula (Peck) Peck, Annual Rep. New York State Bot. 157: 93. 1912.
Type: U.S.A.: New York, Catskill Mountains, September, C. H. Peck s.n. (NYS!, holotype).

Species Synopsis:



Pileus mostly 8-30 mm broad, strongly translucent-striate, reddish brown to orange brown. Lamellae pinkish flesh color. Stipe up to 70 mm long, gracile, glabrous, not striate, appearing cartilaginous when fresh, often somewhat darker than pileus; basal mycelium white. Basidia 4-sterigmate. Cheilcystidia lacking. Basidiospores mostly 7-10 µm diam. (excluding ornamentation), globose, echinulate; spines 1.4-2.8 µm long, > 1.2 µm wide at base. Eastern North America, often in wet moss.

Habitat and Distribution:



Scattered to gregarious; in damp areas, often among wet mosses, usually not among Sphagnum, in mixed forests with Tsuga canadensis (L.) Carr. and/or other Pinaceae and Fagaceae, eastern North America. Material of this taxon has not been reported from Europe. In eastern North America it is common and abundant. See Specimens Examined for the list of species studied.

Observations:



Laccaria striatula is easily recognizable by its strongly translucent-striate pileus; long, gracile, glabrous, reddish brown stipe; and globose basidiospores with long and wide echinulae. These characteristics differentiate it from L. laccata var. pallidifolia and L. ohiensis, the two taxa to which it is phenetically most similar. Due to the difficulty of interpreting dried herbarium material lacking macromorphological notes, it is sometimes difficult to differentiate between material of L. ohiensis and L. striatula.
Tissue cultures of this taxon were not obtained but homokaryotic isolates and reconstituted dikaryons were white and grew moderately fast on all employed media. Homokaryotic isolates of L. striatula were intersterile with tested isolates of other members of the L. laccata complex (Mueller, 1991c). Material of this taxon was not included in our RFLP analyses (Gardes et al., 1990, 1991a).
Singer (1946), Orton (1960), Bon (1983) and others have treated this name as referring to a taxon with bisterigmate basidia. An examination of the type specimen, however, showed it to have 4-sterigmate basidia and that concept is used here.
This taxon is abundant in wet mossy areas in the mountains of Georgia, North Carolina, South Carolina, Tennessee, and Nova Scotia. It has also been collected in southern Ontario and northern Michigan and Wisconsin.
Mueller (1985) incorrectly used the name L. glabripes McNabb for this taxon. Aguirre-Acosta and Pérez-Silva (1978) reported L. glabripes from Mexico. Although I have not seen their material, it is likely that it is referable to L. striatula not L. glabripes. All other reports of L. glabripes have come from Australia and New Zealand. I have not encountered material of L. striatula among the specimens that I have collected and examined from Costa Rica and South America.

Macromorphology:



Pileus 6-30(-36) mm broad, convex, occasionally becoming plane, often depressed, strongly translucent-striate when fresh, occasionally plicate-striate, finely fibrillose, occasionally finely fibrillose-scaly near disc, hygrophanous, reddish brown to orange-brown ("Hazel," "Cinnamon-Rufous" or "Vinaceous-Rufous"), then lighter in color ("Salmon Color," "Seashell Pink" or "Pinkish Buff"); disc occasionally darker in color ("Hay's Russet"); margin incurved to decurved, becoming plane, entire to undulate; context thin, concolorous. Lamellae sinuate to adnate, close to subdistant to distant, relatively narrow to broad, thin to thick, pinkish flesh color ("Flesh-Ocher" or "Pale Flesh Color"). Stipe 20-70(-103) x 1-4(-8) mm, equal, occasionally slightly bulbous, glabrous, appearing cartilaginous when fresh, reddish brown, concolorous with disc or darker ("Kaiser Brown," "Hazel," "Cinnamon-Rufous" or "Onion-skin Pink"). Basal mycelium white.

Micromorphology:


Pileipellis of interwoven hyphae with scattered to numerous small fascicles of ± perpendicular hyphae; fascicles usually composed of 5-15 hyphae; terminal cells of fascicular hyphae 33-85 x 6-18.5 µm, filamentous, subclavate, clavate, subcapitate or ventricose-rostrate, occasionally strangulate; walls up to 0.5 µm thick, hyaline to light yellowish brown; contents hyaline to light yellowish brown. Pileus trama tightly interwoven, morphologically undifferentiated, hyaline, light yellowish brown toward pileipellis. Lamellar trama parallel; hyphae 3-11(-27) µm diam, thin-walled, hyaline to light yellowish brown; cells filamentous to barrel-shaped. Subhymenium morphologically undifferentiated. Basidia 30-59.5 x 8-14.5 µm, clavate, hyaline; sterigmata 4, up to 11 µm long. Cheilocystidia not observed. Basidiospores (excluding ornamentation) [265/13] 7-10(-12) x 7-10(-12) µm [ = 8-9(-10) x 7.7-9(-10) µm], Q = 1(-1.12) [ = 1-1.04], globose, rarely subglobose, hyaline, echinulate; echinulae 1.4-2.8 µm long, up to 1.8 µm wide at base, crowded; hilar appendix 1.3-2 µm long, prominent, truncate; plage present; contents occasionally uniguttulate. Basal mycelium hyphae mostly 2-12.5 µm diam, tightly interwoven, hyaline; cells filamentous to barrel shaped.