Darkera parca H.S. Whitney, J. Reid & Piroz., Canadian

Crous, Pedro W., Müller, Michael M., Sánchez, Romina M., Giordano, Lucrecia, Bianchinotti, M. Virginia, Anderson, Freda E. & Groenewald, Johannes Z., 2015, Resolving Tiarosporella spp. allied to Botryosphaeriaceae and Phacidiaceae, Phytotaxa 202 (2), pp. 73-93 : 83

Darkera parca H.S. Whitney, J. Reid & Piroz., Canadian Journal of Botany 53: 3053 (1975); Fig. 4

Synonyms: Sphaeropsis parca Berk. & Broome, Annals and Magazine of Natural History 5: 420 (1850)

Phoma parca (Berk. & Broome) Sacc., Sylloge fungorum (Abellini) 3: 100 (1884)

Macrophoma parca (Berk. & Broome) Berl. & Voglino, Atti della Società Veneziana-Trentina-Istriana di Scienze Naturali 10: 191 (1886)

Sirococcus parcus (Berk. & Broome) M. Morelet , as “parca ”, Bulletin de la Société des Sciences Naturelles et d’Archéologie de Toulon et du Var 205: 9 (1973)

Tiarosporella parca (Berk. & Broome) H.S. Whitney, J. Reid & Piroz., Canadian Journal of Botany 53: 3055 (1975)

Conidiomata globose, immersed to erumpent, brown, up to 250 μm diam, opening by means if an irregular rupture; wall of 3–6 layers of brown textura angularis. Conidiophores reduced to conidiogenous cells. Conidiogenous cells lining the inner cavity, hyaline, smooth, ampulliform to subcylindrical, proliferating percurrently at apex, mono- to polyphialidic, 8–15 × 3–4 μm. Paraphyses intermingled among conidiogenous cells, hyaline to pale brown, smooth to verruculose, 0–4-septate, subcylindrical with obtuse ends, 30–55 × 2–3 μm. Conidia solitary, hyaline, smooth, guttulate, fusoid-ellipsoid to subcylindrical, straight to curved, apex apiculate, tapering at base to truncate hilum, 2 μm diam, (22–)25–30(–41) × (6–)7(–7.5) μm; apex with flared mucoid appendage, up to 15 μm long, 13 μm diam (based on CPC 23904).

Culture characteristics:— Colonies dirty white on all media, with moderate aerial mycelium and feathery margins, covering dish in 1 mo.

Specimens examined:— SIBERIA. Buriatia , Zum Murino, Tunkinski-valley, on needles of P. abies , 14 Nov. 2008, M. Müller, Ir 406 = CPC 23903 ; roadside between Zum Murino and Irkutsk, healthy needles of needles of P. abies var. obovata , 14 Nov. 2008, M. Müller, Ir 419 = CPC 23904 .

Notes:— Although the connection between the sexual and asexual morph was based on association, and not confirmed via culture studies, we regard this link as probably correct, as tiarosporella-like morphs have been linked to more than one species of Darkera ( Whitney et al. 1975) . Furthermore, the present fungus corresponds very well with the asexual morph identified by Whitney et al. (1975) from Canada as T. parca (conidia (20–)23–40 × 4–6(–7) μm), and linked to Darkera parca . However these dimensions differ slightly from those provided later by Nag Raj (1993) for D. parca , which are larger, (29–)35–43 × 9–12 μm. It could well be that the original species described from the UK as Sphaeropsis parca Berk. & Broome is not conspecific with the Canadian D. parca . For this reason we propose to retain the name D. parca H.S. Whitney, J. Reid & Piroz. 1975 for the collections from Canada and Siberia. Further cultures and molecular data need to be studied to resolve the issue if Darkera parca from Canada is conspecific with Sphaeropsis parca Berk. & Broome 1850 from the UK.

Figures

FIGURE 4. Darkera parca (CPC 23904). A. Conidiomata on PNA. B. Conidiomata on OA. C–E. Conidiogenous cells. F–H. Conidia. Scale bars:A = 250 μm, all others = 10 μm.