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Puccinia xanthosiae McAlpine

Description
Uredinia on lower leaf surface, subepidermal, erumpent, round, up to 1 mm, yellowish brown, peridium present.

Urediniospores globose, subglobose or obovoid, apex obtuse, yellowish brown, 23‒29 × 20‒24 µm; wall 2‒3 µm thick, finely echinulate, with 2‒3 equatorial germ pores.

Hosts
Host family: Apiaceae
Host species: Xanthosia rotundifolia

Distribution
WA

Comments
Puccinia xanthosiae is a native rust described by McAlpine (1906) on the endemic plant genus, Xanthosia. McAlpine (1906) described the urediniospores as 30‒37 x 24‒28 µm, which is larger than in our current description. Puccinia xanthosiae was closely related to the rusts on Goodeniaceae, Stylidiaceae and P. lagenophorae on Asteraceae in a systematic analysis (Hyde et al. 2014). These rusts may be the result of sympatric speciation after host jumps in a shared environment (McTaggart et al. 2014).

Highslide JS
Puccinia xanthosiae on Xanthosia rotundifolia - BRIP 57729.
Highslide JS
Puccinia xanthosiae on Xanthosia rotundifolia - BRIP 57729.
Scale bar = 1 cm.
Highslide JS
Urediniospores of Puccinia xanthosiae on Xanthosia rotundifolia - BRIP 57729.
Scale bar = 10 µm.
Teliospores of Puccinia xanthosiae on Cyperus rotundus - BRIP 52662.
Scale bar = 10 µm.