Milesina whitei (Faull) Hirats., Memoirs of the Tottori Agricultural College 4: 123 (1936)

Bubner, Ben, Buchheit, Ramona, Friedrich, Frank, Kummer, Volker & Scholler, Markus, 2019, Species identification of European forest pathogens of the genus Milesina (Pucciniales) using urediniospore morphology and molecular barcoding including M. woodwardiana sp. nov., MycoKeys 48, pp. 1-40 : 1

Milesina whitei (Faull) Hirats., Memoirs of the Tottori Agricultural College 4: 123 (1936) Figure 6q, r

Polystichum aculeatum (L.) Roth (syn. P. lobatum L, Aspidium lobatum Sw.). Croatia, Dalmatia: Castelnuovo, 25 Apr 1914, O. Jaap (FH, FH 01146298, type).

Polystichum setiferum (Forsk.) Moore ex Woynar., Austria, Steiermark: Deutschlandberg, Klause, Laßnitz, northern bank of the river, rock, 31 Jul 2018, M. Scholler & C. Scheuer (KR, KR-M-0050248); Switzerland, Ticino: Locarno, Cugnasco, Valle di Cugnasco, ravine, 9 Dec 2017, L. Beenken (KR, KR-M-0044953); Vaud, Montreux, Gorges du Chadron, 30 Apr 2011, T. Brodtbeck, II (KR, KR-M-0049177).

Polystichum sp. Austria, Steiermark: Possruck, ravine, 19 Nov 1972, J. Poelt (KR, KR-M-0039378).

Description.

Urediniospores hyaline, ellipsoidal, obovoidal to oval, 27.5-40.0 × 16.5-25.0 µm, mostly 27.5-37.5 × 17.5-22.5 µm; wall 0.5-1.0 µm, mostly 0.8-1.0 µm thick; echinulate without spine-free areas, spines 1.8-2.8 µm, mostly around 1.8-2.5 µm long, irregularly distributed, straight and perpendicular to the wall, distance between spine bases 1.0-8.0 µm, mostly 1.5-5.0 µm, spine base 0.5-1.2 µm, mostly 0.8-1.1 µm diam.; germ pores scattered, 8-15 (17), mostly 9-13, 1.3-3.0 µm, mostly 2.0-2.5 µm diam., Ø 2.3 µm diam.

Comment.

The North American Milesina polystichi (Wineland) Grove (= Milesia polystichi Wineland) on Polystichum munitum (Kaufl.) Presl. is considered conspecific with M. whitei by several authors (e.g. Gäumann 1959). We were able to study isotype material (USA, Oregon, Granite Pass, 5 Sep 1916, leg. R.J. Weir, PUR 004047) and found urediniospores with mostly 5 to 6 germ pores, i.e. many fewer than in M. whitei . Due to this striking difference, they are possibly different species.