Barclay's Asian Rubus rust - Phragmidium barclayi

This rust attacks species of Rubus native to Asia. None of these host species are economically important nor are they closely related to species of economic importance. Thus, this rust species does not appear to be a threat to North American berry crops.

Phragmidium barclayi Dietel, 1890

Uredinia hypophyllous (on lower surface of leaves), scattered, small, orange, paraphysate; urediniospores globose, subglobose, obovate or ellipsoid, 17-26.5 × 15.5-19.5 µm, wall 1.1-1.5 µm thick. Paraphyses clavate, subclavate, curved, 40-77-12 × 23 µm, 1.1-2.5 µm thick.

Telia hypophyllous, scattered, minute, forming spot 0.5-2.0 mm diam, black, pulverulent; teliospores cylindrical, 5-8 celled, mostly 6 celled, 62-137 × 29-39 µm; walls orange to brown, sparsely verrucose, 1.3-5.0 µm thick, apiculus lacking. Pericels hyaline, 53.5-117.5 × 10.0-15.5 µm.

See Kakishima et al. (2002) for a more detailed description.

Host range: Mostly Rubus subgenus Idaeobatus, specifically R. austrotibetanus, R. hoffmeiterianus, R. niveus, but also Rubus subgenus Rubus, specifically R. koehleri.

Geographic distribution: Asia (China, India, Nepal, Pakistan)

Confusion exists about what is Phragmidium barclayi. Although Barclay (1890) did not describe Phragmidium rubi, he suggested that a specimen from Asia was the same as P. rubi Pers. : Fr., now considered a synonym of Phragmidium bulbosum. Dietel (1890) described Phragmidium barclayi from material that was Phragmidium rubi sensu Barclay.

References:

Ahmad, S. 1956. Uredinales of West Pakistan. Biologia (Lahore) 2: 27-101.

Arthur, J.C., and Cummins, G.B. 1933. Rusts of the Northwest Himalayas. Mycologia 25: 397-406.

Kakishima, M., Ono, Y., Wahyuno, D., Zhou, X., and Zang, M. 2002. Rust fungi of Phragmidium (Uredinales) from Yunnan Province, China, collected in 1998. Bull. Natl. Sci. Mus., Tokyo, B. 28: 11-18.

Zhuang, J.-Y., and Wei, S.-X. 1994. An annotated checklist of rust fungi from the Mt. Qomolangma region (Tibetan Everest Himalaya). Mycosystema 7: 37-87.

Nomenclature

Specimens in BPI

Additional distribution data

Suggested citation: Yun, H.Y. Systematic Mycology and Microbiology Laboratory, ARS, USDA. . Invasive Fungi. Barclay's Asian Rubus rust - Phragmidium barclayi. Retrieved November 21, 2009, from http://nt.ars-grin.gov/sbmlweb/fungi/index.cfm .