Ramaria calvodistalis R.H. Petersen

Petersen, Ronald H., Hughes, Karen W. & Justice, Jay, 2014, Two new species of Ramaria from Arkansas, MycoKeys 8, pp. 17-29 : 23-26

Taxon classification Fungi Gomphales Gomphaceae

Ramaria calvodistalis R.H. Petersen sp. nov. Figs 6, 7

Holotype.

United States, Arkansas, Baxter Co., vic. Big Flat, Rte 341, Moccasin Creek Trailhead, Ozark National Forest, 36°02'N, 92°21'W, 24.X.2013, coll. RHP, TFB 14431 (TENN 69095).

Etymology.

Calvus = bald; distalis = referring to the spore wall opposite the hilar appendage.

Diagnosis.

1) Member of Ramaria subg. Laeticolora ; 2) clamp connections absent from all tissues; 3) acanthodendroid hyphae absent; 4) stipe small, pruinose, white, without color change where handled or rubbed; 5) branches and apices yellow; 6) type locality northern Arkansas; 7) ITS sequence unique in the subgenus; (GenBank accession KJ416132).

Adult basidiomata (Fig. 6) -15 × 12 cm, repeatedly branched, coralloid; young basidioma with discrete base, white, hardly canescent or pruinose; adult basidiome base falsely fasciculate (i.e. discrete but with narrow grooves and crevices giving the appearance of several stipes strongly compressed), snow white, finely canescent where free of soil particles; abortive branchlets common, white; stipe flesh white, solid, firm, gelatinous only in areas of degeneration or maggot-infestation, without brown bands or patches; lower branches "orange buff" (5A5), upward becoming "warm buff" (5A4) to "antimony yellow" (4B6); apices rounded, concolorous. Odor none. Taste none; consistency mealy. No bruising reactions on surface or flesh.

Habitat and phenology.

Possibly associated with deciduous trees from local forests of Quercus , Carya , Carpinus and occasional Pinus , solitary to gregarious, often in troops or rings; fruiting in late autumn.

Hyphae of stipe canescence 2-4 μm diam, relatively brittle and straight, firm-walled, rarely septate, without clamp connections, non-refringent; acanthodendroid hyphae absent; in non-gelatinous areas of stipe flesh hyphae 3-12 μm diam, tortuous, frequently branched, thick-walled (wall -0.7 μm thick), often refringent (PhC), without clamp connections; rare ampulliform swellings (without clamp connection) -16 μm diam, delicately ornamented internally, not unusually thick-walled. Hyphae of upper branch trama appearing subgelatinous under low magnification, but when squashed in KOH shown to be free, 3.5-12 μm diam, without clamp connections, firm-walled (wall -0.5 μm thick); cells filamentous to elongate-barrel-shaped. Basidioles often misshapen, paraphysoid, with various small lobes or sinuate shapes. Basidia (Fig. 7A) 55-72 × 12-13 μm, clavate with somewhat bulbous apex, 4-sterigmate, occasionally with an asymmetric lobe, without clamp connections; contents usually with proximal and distal refringent guttules. Basidiospores (Fig. 7B) (12 –)14– 15 × 4.5 –5.0(– 5.5) μm (Q = 2.67-3.33; Qm = 3.03; Lm = 14.05 μm), generally boletoid, with scattered small cyanophilous warts and patches through midsection of the spore but absent from the distal end which appears bald; contents with amorphous deposits (PhC); wall slightly thickened through midsection (wall -0.5 μm thick).

Commentary.

Care must be taken to ascertain the condition of basidial septa. In clamped basidia, subsequent basidioles arise through the subtending clamp. In clampless basidia (as above), subsequent basidioles arise in precisely the same fashion, arising just below the subtending septum, but without the telltale evidence of a clamp connection. Additional care is required to ascertain that both tramal hyphae and basidia are without clamps. Spores are among the longest in the subgenus and largely as a result, Qm value is high. Spore outline is distinctly boletoid with slight suprahilar depression. First impression was of delicately marbled stipe flesh (i.e. with small, scattered areas of hyphae with gelatinized walls), but closer examination revealed scattered degeneration of inner stipe flesh through maggot infestation. Lower and middle branches as well as apices are essentially unicolorous, straw yellow or dull ochraceous yellow. Juvenile branches exhibit a slight blush of pale pinkish buff, but this soon fades and slowly turns to the adult yellow shades.

In the three days of the NAMA foray, numerous collections of this species were made. Basidiomata seem to occur in troops and "fairy rings" under deciduous trees and are often somewhat bulky. Stipes are not deeply rooted and are easily dislodged, but adult stipes seem consistently maggot-ridden. Because a new taxon was not anticipated, only the type collection was preserved. Although the literature dealing with Ramaria of the Pacific Northwest has been summarized at least twice over the decades ( Marr and Stuntz 1973; Exeter et al. 2006), modern literature is unavailable for Ramaria east of the Rocky Mountains except in fragments. Even less adequate is coverage of central United States, including the Ozark Mountains of Arkansas.

Marr and Stuntz (1973) described a small group of Ramaria taxa which exhibited cyanophilous “acantho-dendroid” hyphae in the outer stipe flesh, using Ramaria cystidiophora as the focal taxon, but including several infraspecific taxa. In all cases, stipes are white and pruinose and all upper basidiome parts are some shade of yellow. Exeter et al. (2006) illustrated basidiomata of several of the infraspecific taxa in the Ramaria cystidiophora complex, which macroscopically are reminiscent of Ramaria calvodistalis , so a special search was made for acanthodendroidal hyphae. Not only were no such hyphae found, but Ramaria calvodistalis lacks clamp connections, also a violation of the Ramaria cystidiophora complex.

If the key to clampless taxa in Exeter et al. (2006) is employed, no adequate match is found. Ramaria longispora produces spores of appropriate dimensions, but while upper branches and apices are yellow, lower branches are cantaloupe or pinkish salmon. In the working key of one of us (RHP), no match is found because the combination of yellow basidiome coloration, lack of clamp connections and long spores eliminates all candidates.

Ramaria admiratia and Ramaria calvodistalis LSU sequences place them near sequences representing brightly colored Ramaria species ( Ramaria aurantiisiccescens and Ramaria araiospora ) in subgenus Laeticolora (Fig. 8). ITS divergence within this subgenus is large, however, and Ramaria admiratia and Ramaria calvodistalis ITS sequences are only 86% similar to each other. Ramaria calvodistalis ITS sequences are most closely related (>97%) to two unnamed collections from Mexico (GenBank KC152173 and KC152176). These three collections differ from each other predominantly in the number of bases in repeat areas and probably represent the same lineage. We have previously noted that Mexico may have served as a glacial refugium for taxa now found further north ( Hughes et al. 1999; Lickey et al. 2002; Hughes and Petersen 2004). There are no close blast matches to Ramaria admiratia in GenBank or in our sequence data set. A number of taxa in Fig. 8, based on assigned names, appear to be polyphyletic suggesting that morphological species concepts harbor more than one cryptic species or that misidentifications are common.