Search on : Taxa descriptions

 


   
Description type:Original description 
Description:Ramaria rubrievanescens sp. nov. (P1. I Fig. 3)
Holotypus M-584 ad rivum Sloan prope viam, in comitatu Snohomish pagi washingtoniaci 9/26/67 lectus, in herbario SUCO conservatus.
Basidiocarp: Habitat: terrestrial, growing in a forest of Western Hemlock. Color: stipe of fruiting body milk-white discoloring yellowish, bruising "brownish violet" (11D6), primordial branch tips flushed with "shell pink"(6-8A3), pink color ation lost during maturation and soon after collecting, mature branches "yellowish white" (4A2-3), context white. Stipe of dried basidiocarps "yellowish white" (4A2) with small areas of "yellowish brown" (5D8), branches drying one or two shades lighter than "grayish orange" (5B3), context "yellowish white" (4A2). Taste-slightly similar to nuts. Odor: faintly sweet. Form: basidiocarps nearly as broad as tall, 7-8 x 6.5-8.5 cm (M-809, 20 x 18 cm). Stipe single, cylindric or conic, massive, 3.5-9 x 2-4.5 cm, with occasional small abortive or primordial branches; branch systems crowded, vertically compressed on the stipe and curving inwards about 1-4 cm long, branching 2-5 times, lower branches usually very short and broad, 2-4 cm diam, connation frequent in lower parts, upper branches mostly 1-4 mm diam, axils u-shaped, slightly divergent, bifurcate to pluridigitate near apices; apices obtuse, rounded or decidedly blunt. Consistency: punky firm when fresh, drying hard.
Macrochemical Reactions: Context of stipe amyloid, however, reaction may be slow (?); significant color changes do not appear within 15 min of application to branch sections of pyrogallol, a-napthol, guaiac, guaiacol, phenol, and aniline.
Microscopic structures: Spores: average 11.7 x 4.9u(M-584), range 11-13 x 4-5.5 µm , mummy-shaped, ventral surface curving sharply to the apiculus, ornamented with conspicuous, cyanophilous striae, spores "light yellow" (4A4) in deposit.
Hymenium: basidia clavate, 55-87 x 8-11 µm , basally clamped, containing strongly cyanophilous globules, mostly 4-sterigmate, occasionally 2;sterigmata 3-7 µm long, straight, not divergent, also containing cyanophilic inclusions; hymenium about 60 µm thick. Subhymenial hyphae: interwoven, 2.5-4.5 µm diam, thin-walled, clamped, with globular cyanophilous inclusions. Contextual hyphae: interwoven in the stipe, branches mostly thin-walled, 0.25-1 µm , wall surface smooth to fluted, ampulliform swellings near septa 9-12 µm diam, walls of the swellings distinctly ornamented; clamps frequent, closed or open, the clamp cell sometimes enlarged; gleoplerous hyphae interweaving throughout context, generally 3-5 µm diam, in vesicular regions up to 12 µm diam.
Discussion: The most unusual feature of this species is the evanescence of the pink color, present only in primordial branch tips. Terminal branches of M-584 were distinctly pink when collected and a day later the color changed to yellowish white. Presumably this loss of color would also occur during the normal maturation process. Despite this startling phenomenon, the characteristic is difficult to deal with taxonomically. Unless the specimens are collected while immature, the fruiting bodies are apt to be described as white or cream-colored. Mature fruiting bodies are easily confused with those of R. strasseri, but the two species differ in spore dimensions. The thick stipe, numerous, crowded branches, white fruiting bodies bruising when cut, and short striate-ornamented spores (average 11.1 x 4.7 µm ), characteristic of one element of the R. crassipes type (NYS), indicate close relationship of this species with R. rubrievanescens. Further research is necessary to determine if R. secunda (Berk.) Corner is a prior legitimate epithet for the shortspored R. crassipes.
Some of Dr. R. H. Petersen's specimens from Northern Idaho (R.H.P. 3703, 3835. TENN) have spore morphology and rubribrunnescent qualities similar to those of R. rubrievanescens, but unlike R. rubrievanescens the reddish pigment seems to have persisted at maturity. It is possible that the characteristics of R. rubrievanescens and R. rubripermanens may intergrade. This relationship needs to be investigated further.
 
Taxon name: