Rust Fungi of Southeast Asia

Phragmidium mexicanum (Mains) H.Y. Yun, Minnis & Aime

Description
Uredinia on lower leaf surface, subepidermal, erumpent, round, yellow, peridium present.

Urediniospores globose to subglobose, apex obtuse, hyaline to yellow when fresh, 16-18 × 16-18 µm; wall 1.0-1.5 µm thick, apex unthickened, densely echinulate.

Telia on lower leaf surface, subepidermal, erumpent, dome-shaped, black, peridium present.

Teliospores cylindrical, apex rounded, 3 celled to 4 or more celled, reddish brown, 47-74 × 22-27 µm; wall 2-3 µm thick, 3-5 µm thick at apex, smooth, pedicel persistent, up to 43 µm.

Specimens cited in description:
- BRIP 58378.

Hosts
Host family:
- Rosaceae

Host species:
- Potentilla indica

Distribution
Vietnam

Highslide JS
Phragmidium mexicanum on Potentilla indica - BRIP 58378.
Highslide JS
Phragmidium mexicanum on Potentilla indica - BRIP 58378.
Scale bar = 1 cm.
Highslide JS
Urediniospores of Phragmidium mexicanum on Potentilla indica - BRIP 58378.
Scale bar = 10 µm.
Highslide JS
Teliospores of Phragmidium mexicanum on Potentilla indica - BRIP 58378.
Scale bar = 10 µm.