Ramaria admiratia R.H. Petersen

Petersen, Ronald H., Hughes, Karen W. & Justice, Jay, 2014, Two new species of Ramaria from Arkansas, MycoKeys 8, pp. 17-29 : 19-22

Taxon classification Fungi Gomphales Gomphaceae

Ramaria admiratia R.H. Petersen sp. nov. Figs 1-5

Holotype.

United States, Arkansas, Searcy Co., grounds of Shepherd of the Ozarks, 36°00'10"N, 92°28'28"W, 24.X.2013, coll. Carl Davis and Therese Martin (NAMA), TFB 14450 (TENN 69114).

Etymology.

admiratia = surprise, astonish, referring to the acanthodendroid hyphae in the outer stipe context.

Diagnosis.

1) Member of Ramaria subg. Laeticolora sect. Formosae ; 2) clamp connections absent from all tissues; 3) acanthodendroid hyphae common in outer stipe flesh and surface; 4) stipe large, pruinose, white but easily staining to brown where handled or rubbed; 5) branch apices bright orange red; 6) type locality, northern Arkansas; 7) ITS sequence unique in the subgenus; (GenBank ITS accession KJ416133).

Basidiomata (Figs 1-4) robust, fleshy, -16 × 14 cm, repeatedly branched, coralloid. Stipe portion massive (Fig. 3), from discrete to 2-3 large conjunct stipes, fleshy, rounded, with minimum external mycelium, superficially white-pruinose where undisturbed, extensively "Mikado brown" (7C6) where rubbed; flesh off-white, solid, moist (not slippery), very finely marbled, very slowly becoming tan where sliced; abortive branchlets in small, vertical clusters, easily brown. Lower branches "light ochraceous buff" (5A4), upward "capucine orange" (5A6) to "Mikado orange" (6A6), in age "ochraceous salmon" (6A6) to "light ochraceous salmon" (6A4); internodes diminishing gradually; branch apices (Fig. 4) (ultimate 3-4 mm) rounded, ultimately dentate, "Grenadine red" (8A8), becoming concolorous to "capucine yellow" (5A8). Odor none. Taste none. 5% aqueous FeSO4 on stipe flesh = no color change.

Habitat and phenology.

Generally second-growth hardwood forest of Quercus with scattered Carpinus , Carya and Acer ; sole specimen from late autumn.

Surface of lower stipe covered with felty white tomentum; tomentum hyphae 3-4 μm diam, clampless, firm- to thick-walled (wall -0.5 μm thick), hyaline; acanthodendroid hyphae (Fig. 5B) common, refringent (PhC), strongly cyanophilous, 3-4 μm diam, thick-walled (wall -0.7 μm thick), appearing thorny. Hyphal construction of stipe medulla monomitic (with gloeoplerous hyphae), liberating significant debris in squash mounts; hyphae 4-14 μm diam, firm- to thick-walled (wall -0.5 μm thick), hyaline, clampless; ampulliform septa 7-17 μm diam, ampulliform to subspherical, thick-walled (wall -1 μm thick), delicately ornamented; gloeoplerous system represented by short lengths of cyanophilous hyphae with occasionally swellings. Hyphae of upper branch trama strictly parallel, tightly packed, thin-walled, clampless; cells filamentous to keg-shaped; occasionally slender (3-4 μm diam), non-refringent hyphae meandering through trama. Gloeoplerous system represent by occasional short lengths of strongly cyanophilous hyphae without septa. Basidia (Fig. 5A) 45-57 × 11-13 μm, clavate (not significantly bulbous), clampless, 4-sterigmate; contents multiguttulate (guttules refringent, apparently scattered throughout; PhC). Basidioles filamentous, digitate, uninformative. Basidiospores (Fig. 5B) 12-14.5 × 4.5 –5.5(– 6) μm (Q = 2.27-2.80; Qm = 2.52; Lm = 13.20 μm), ellipsoid, distinctly roughened in profile but ornamentation indistinct (PhC); contents heterogeneous with one or more non-refringent vacuoles (vacuoles amorphous, appearing empty on slightly darker background; PhC); ornamentation moderately cyanophilous, of narrow, axially oriented, meandering low ridges, appearing scattered, small and low in profile.

Commentary.

Superficially, basidiomata of Ramaria admiratia resemble those of Ramaria cokeri through sordid yellow branches with reddish apices and brunnescent stipe. Ramaria cokeri belongs in Phaeoclavulina ( Giachini 2004; Giachini and Castellano 2011; Giachini et al. 2001, 2010 = Ramaria subg. Echinoramaria ) with echinulate basidiospores, clamped tramal hyphae and basidia, and rubribrunnescent (not brunnescent) stipe surface.

As noted by Christan (2008) taxa with cyanophilous dendrohyphidioid stipe tomentum hyphae are more common than originally envisioned ( Marr and Stuntz 1973). Most common among them are taxa with yellow branches and apices and rather small stipes. In taxa resembling Ramaria admiratia , centering around Ramaria cystidiophora , varieties have been described based largely on odors (vars. anisata, fabiolens) and rubribrunnescent stipe (var. maculans) (see Marr and Stuntz 1973; Exeter et al. 2006). Conversely, Ramaria admiratia basidiomata exhibit a large, strongly brunnescent stipe and orange to red-orange branches and apices.

The terms “monomitic,” “dimitic”, etc. were coined by E.J.H. Corner (1932) to describe the anatomy of various polypore basidiomata and have proven useful in subsequent, widely used taxonomic schemes. Dimitic referred only to presence of two hyphal types, specifically generative and skeletal, definition of the latter being philosophically augmented over some decades. Donk (1971) and Petersen (1975), conversely, while accepting the anatomical observations, linguistically considered dimitic to describe any tissue in which two hyphal types were found, whether generative and skeletal, generative and gloeoplerous, generative and acanthanophysoid, etc., as long as the hyphal types were accurately described. In the case of Ramaria admiratia (and other fleshy fungi with various second hyphal types), one is confronted with Cornerian terminology in which “monomitic” actually includes two hyphal types: generative plus cyanophilous, characteristically branched acanthophysoid hyphae.