U.S. Department of Agriculture, Agricultural Research Service Systematic Mycology and Microbiology Laboratory - Invasive Fungi Fact Sheets Asian pistacio rust - Pileolaria pistaciae Two species of Pileolaria cause rust diseases on species of Pistacio. While Pileolaria terebinthi known from the Middle East and Europe will infect the commercial pistachio, it is not known if the Asian P. pistaciae will do so. Neither species is known in North America. Pileolaria pistaciae F.L. Tai & C.T. Wei 1933 Spermogonia and aecia unknown. Uredinia epiphyllous, mostly amphigenous, dark-brown to brown, erumpent, powdery, 1-5 mm diam; urediniospores ellipsoid to fusiform, acuminate at apices, rounded at base, 30-46 × 15-20 µm, walls pale brown, irregularly verrucose, 1.5-2 µm thick at sides, 4-8 µm thick at apices, with four equatorial germ pores. Telia epiphyllous, dark-brown; teliospores discoid or very broadly ellipsoid, 23-30 × 16-25 µm, walls 2.5-3.5 µm, chestnut-brown, rugose or reticulated, pedicels hyaline, 30-50 µm. See Hiratsuka et al. (1992) for a more detailed description. Host range: Pistacia chinensis, P. weinmannifolia (Anacardiaceae) Geographic distribution: Asia (China, India, Japan, Philippines, Taiwan) Cummins (1937) compared this fungus with Pileolaria terebinthi also on Pistacia spp. in Asia but that rust has irregularly papillate urediniospores with thinner walls and teliospores that are lighter in color and have shorter pedicels. It is not known if Pileolaria pistaciae will attach Pistacia vera, the commercial pistachio. References: Bhardwaj, L.N., and Sharma, R.C. 1994. Some new fungal diseases of Pistacia integerrima from Himachal Pradesh. Indian Forester 120: 545-547. Zhuang, W.-Y., Ed. 2001. Higher Fungi of Tropical China. Mycotaxon, Ltd., Ithaca, NY, 485 pages. Suggested citation: Yun, H.Y..Systematic Mycology and Microbiology Laboratory, ARS, USDA. Invasive Fungi. Asian pistacio rust - Pileolaria pistaciae. Retrieved September 26, 2021, from /sbmlweb/fungi/index.cfm . Use this link to revisit SMML website Telia of Pileolaria pistaciae on Pistacia chinensis (x3.2) Teliospores of Pileolaria pistaciae on Pistacia chinensis (x40) Teliospores of Pileolaria pistaciae on Pistacia chinensis Teliospores of Pileolaria pistaciae on Pistacia chinensis (x20) (x40) .