Rust Fungi of Southeast Asia

Hemileia vastatrix Berk. & Broome

Description
Uredinia on lower leaf surface, occasionally on both leaf surfaces, suprastomatal, erumpent, round, emerging through stomata, densly scattered, up to 25 mm when aggregated, yellow when young, turning hyaline to subhyaline with age.

Urediniospores reniform to subpolyhedrally irregular, apex obtuse, hyaline, 22-36 × 18-28 µm; wall 1-1.5 µm thick, verrucose on convex face, smooth on the straight or concave face.

Telia on lower leaf surface, formed from uredinia, suprastomatal, erumpent, dome-shaped, white.

Teliospores globose to irregular, apex rounded, hyaline, 16-25 × 19-22 µm; wall 1 µm thick, smooth.

Specimens cited in description:
- BRIP 54139 (collected in East Timor).

Hosts
Host family:
- Rubiaceae

Host species:
- Coffea arabica

Distribution
Philippines

Highslide JS
Hemileia vastatrix on Coffea arabica.
Highslide JS
Urediniospores of Hemileia vastatrix on Coffea arabica - BRIP 54139.
Scale bar = 10 µm.