Search on : Taxa descriptions

 


   
Literature:
 
Page number:66 
Description type:Non-original description 
Description:Ramaria flavula (Atkinson) Petersen, comb. nov.
Basionym: Clavaria flavula Atkinson. 1908. Ann. Mycol.6: 56. [!]
Text fig. 6.
Type specimen (holotype): CUP - Ithaca, N.Y., Fall Creek, "bank below Chemical Building [Cornell University campus]", 22.x.02, coll. C. Thom, det. Atkinson, no. 14113. [cf. Burt. 1922. Ann. Missouri-Bot. Gard. 9: 21, pl. 4 fig. 20: photo]
Fruit body 5 cm high, 4.5 cm broad, without stipe or with many slender stipes arising from a thick basal mat of unknown diameter, involving significant amounts of substrate, repeatedly branched. Basal mat white or off-white when fresh, tough-fibrous to tough-felty within, membraneous at surface, thick and involving significant amounts of substrate, without discernable rhizomorphic strands; stipes slender, up to 2.5 mm thick, densely gregarious to cespitose, flattened somewhat, tapering downward from axils, 30-40 in number from approx. 3 sq. cm of basal mat, buff yellow; axils broadly rounded to lunate; apices minute, acute, dichotomous to cusped; hymenium unilateral, inferior; sterile surface smooth to glabrous, leathery; flesh pliant, tough. Odor and taste not recorded.
Hyphae of basal mat trams, generative, 2.2-4.0 ?m diam, thick-walled (wall often obscuring cell lumen), conspicuously clamped, hyaline, serpentine, rigid; inflated clamps up to 10 ?m broad, with insignificantly thickened°wall (wall up to 1.0 ?m thick), unornamented, clavate. Hyphae of fruit body base trama generative, 2.2-9.0 ?m diam, thick-walled (wall up to 3.7 thick), refringent under phase contrast, conspicuously clamped; inflated clamps as above. Hyphae of upper branch trama 3.7-13.5 y diam, thick-walled (wall up to 3.7 ?m thick), not refringent under phase contrast, interwoven,.clamped; inflated clamps inconspicuous.
Spores (text fig. 6) 8.9-11.1 x 4.1-5.2 ?m (E = 1.85-2.50; Em = 2.08; Lm = 9.73 u), ellipsoid, hardly flattened adaxially but with a shallow suprahilar depression, obviously roughened in profile; contents homogeneous; wall up to 0.3 ?m thick; apiculus not prominent, eccentric, leaving no throat; ornamentation of relatively coarse, prominent, discrete, strongly cyanophilous warts and short ridges, scattered but covering significant wall areas.
Observations: The following characters separate this from others: a) monomitic construction of skeletalized generative hyphae, resembling the construction of fruit bodies of R. rubella; b) unilateral, inferior hymenium; c) buff yellow coloration; and d) large, distinctly ornamented spores. When placed with other taxa in Lentoramaria, the species superficially seems quite alone. Perhaps it is closest to R. suecica which also is humicolous and without skeletal hyphae, but that species is usually stipitate, with invariably amphigenous hymenium, and without skeletalized generative hyphae.
A number of characters bind R. flavula and R. rainieriensis. First; both produce fruit bodies which arise from a basal mat on humus. Second; fruit body color in both is buffy to buffy yellow. Third; the spores of both are unusually large for this subgenus, and distinctly warted, the warts discrete and obvious in cotton blue. Fourth: the skeletalized generative hyphae are of variable diameter and indeterminate in length, unlike those of R. rubella and associates. In R. flavula, however, only skeletalized generative hyphae are present in the fruit body base and the interior of the basal mat, while in R. rainieriensis there is a sharp distinction between the thin-walled generative hyphae and thick-walled skeletalized generative hyphae, much as there is in R. gracilis.
There is always some anxiety in accepting a taxon based on a single specimen, regardless of how distinct the taxon may appear. Nevertheless, in this case, taxonomy is best served by acceptance of the taxon, in the hope that it will be collected again. Atkinson's notes accompanying the specimen are no more informative than the original published description, and notes on color, taste and odor are most needed. Coker (1923) treated C. flavula as a synonym under Clavaria suecica, and Corner (1950) followed Coker's lead. The fruit bodies and basal mat of R. suecica, however, are entirely composed of thin-walled generative hyphae, and the basal mat is much less extensive than in R. flavula. Only the spores are similar.
 
Taxon name: