Anthracoidea eburneae Denchev & T. Denchev, Mycologia Balcanica

Denchev, Teodor T. & Denchev, Cvetomir M., 2016, Anthracoidea caricis-reznicekii (Anthracoideaceae), a new species on Carex reznicekii, and A. eburneae, a new record for the USA, Phytotaxa 244 (1), pp. 69-79 : 75-77

Anthracoidea eburneae Denchev & T. Denchev, Mycologia Balcanica 8: 83, 2011. ( Figs 17–21 )

Sori in ovaries, scattered in the inflorescence, as globose, subglobose or ovoid, black, hard bodies, 0.8–1.4 mm long, when young covered by a thin grayish membrane, later becoming exposed; spore mass of the mature sori powdery on the surface. Spores flattened, in plane view irregular to subpolygonal in outline, occasionally with small protuberances, in plane view (14.5–)16–22.5(–24) × 13–18.5 (19.8 ± 1.3 × 16.4 ± 1.1) μm (n = 50), in side view 10.5–13 μm thick, middle to dark reddish brown; wall unevenly thickened, 1.5–3.0(–3.5) μm thick, sometimes with 1–3 internal swellings, difficult to be observed in dark colored spores, light-refractive areas present; minutely verruculose, warts up to 0.2(– 0.3) μm high, spore profile not affected. In SEM warts isolated or confluent forming small groups or short rows.

Specimen examined: —On Carex eburnea Boott ( Cyperaceae ), USA, Michigan, Mackinac Isl., 10 Jul 1899, coll. E.T. Harper & S.A. Harper 699 (F 1322789).

Literature records (all on Carex eburnea ):— CANADA, Northwest Territories, Mackenzie Mountains, Keele River at Canad. Wildlife Service Camp, 64°12′ N, 127°25′ W, 17 Jul 1970, coll. W.J. Cody 18945 (TUR 66255, ex DAOM 133687, Denchev & Denchev 2011a). CANADA, British Columbia, the Village, Mile 442 Alaska Highway, near Peterson Creek, 26 Jul 1960, coll. I. Kukkonen 535 & J.A. Calder (H, Vánky 2011a, as A. wojewodae Piątek , nom. inval., ICN Art. 39.1). CANADA, British Columbia, Alaska Highway, Mile 431, along Toad River, on a ledge by the road, 26 Jul 1960, coll. I. Kukkonen 529 & J.A. Calder (holotype, TUR 73787; Denchev & Denchev 2011a). CANADA, British Columbia, Mile 397 Alaska Highway, near Rocky Mountain Lodge, McDonald Creek, 24 July 1960, coll. I. Kukkonen 514 & J.A. Calder (H, Vánky 2011a, as A. wojewodae ).

Known host and distribution: —On Cyperaceae : Carex sect. Albae : Carex eburnea , North America ( Canada, USA) ( Fig. 22 ).

Comments: —Three species of Carex belong to section Albae : C. alba Scop. —a Temperate-Eurasiatic species, C. ussuriensis Kom. from East Asia (Far East of Russia, Korean Peninsula, and NE China), and C. eburnea from North America ( Egorova 1999). Carex eburnea is widely distributed on limestone in North America (from Alaska to Newfoundland, and southward into the Ozark Mts, the Cumberland Plateau, and the Southern Appalachian Mts; with southern disjunct populations in Alabama and Mexico) ( Gillespie 2005). In Carex section Albae , another American species, C. mckittrickensis P.W. Ball. (from the Guadalupe Mts, Texas), was recognized in Flora of North America ( Ball & Reznicek 2002) but molecular analyses did not support its segregation from C. eburnea ( Gillespie 2005) .

On sedges in Carex section Albae (on C. alba and C. ussuriensis ), a second species of Anthracoidea , A. caricis-albae (Syd.) Kukkonen , is known ( Denchev & Minter 2010c, Vánky 2011a). The following features are characteristic of A. caricis-albae : (i) subpolygonal to very irregularly polygonal or elongated spores, (ii) presence of conspicuous protuberances, (iii) large size of the spores (up to 30 μm long, sometimes up to 32 μm), and (iv) uneven and unusually thick wall, which may reach up to 7 μm at the angles, protuberances, and the elongated ends of the spores. Anthracoidea eburneae is distinctly different from A. caricis-albae by possessing spores which are more regular and of medium size, with small protuberances (if any) and thinner walls (Denchev & Denchev 2011a).

Our previous (Denchev & Denchev 2011a) and current observations show that the spores of Anthracoidea eburneae in different specimens are variable in number and conspicuousness of the internal swellings of the spore walls. The following cases of predominant spore walls were found: (i) spores with 1–3(–4), more or less well developed internal swellings (the case of TUR 73787), (ii) only some spores with 1–3 internal swellings (difficult to observe in dark colored spores, F 1322789), and (iii) spores with indistinct internal swellings (TUR 66255 ex DAOM 133687).

Carex eburnea is considered to be a widely distributed species on limestone in North America. We anticipate that A. eburneae is more widely distributed, especially in the Midwest and Northeast regions of the USA.

Figures

FIGURE 22. Geographic distribution of Anthracoidea eburneae.

FIGURES 17–21. Anthracoidea eburneae on Carex eburnea. 17. Habit (F 1322789). 18, 19. Spores in LM (18—holotype, 19—F 1322789). 20, 21. Spores in SEM (20—holotype, 21—F 1322789). Scale bars: 17 = 0.5 cm, 18, 19 = 10 μm, 20, 21 = 5 μm.