Exoteliospora osmundae

Exoteliospora osmundae (Peck) R. Bauer, Oberw. & Vánky 1999, in Bauer et al., Mycologia, 669-675 (1999).

Diagnosis: Sori (Figure 1) external on both sides of deformed and hypertrophied leaves of the host plant, yellowish-, cinnamon- to reddish-brown depending on age. Coralloid haustoria present in epidermal cells (Figure 2). Teliospores produced in basipetal chains (Figure 2), globose, subglobose, rarely ellipsoidal, variable in size and ornamentation, 9-18(-23) X 10-19(-23) µm, light to orange-brown; wall 1-1.5 µm thick, smooth to prominently verrucose (Fugues 5-8). Septal pores with non-swollen lips and membrane caps (Figures 13- 16). Teliospore germination unknown. On Osmundaceae, 0. regalis L. and 0. cinnamomea L. Known from several collections in North America

Index Fungorum Number: IF460677

Figure 1. Infected pinnules of Osmunda regalis. Scale bar 1 cm.

Figure 2. Coralloid haustoria in epidermal cells from a freehand section and the mode of teliosporogenesis of Ustilago osmundae = Exoteliospora osmundae. Scale bar = 10 µm.