| Distribution |
Germany, Japan, Korea, Spain, Switzerland |
| Characteristics |
Down hypophyllous, whitish, dense, felt-like. Haustoria filling the host cell partly to almost completely, lobate. Conidiophores emerging through stomata, 20–30 in a fascicle, hyaline, somewhat stout, straight, (216.0–)261.6–355.4–449.2(–542.1) µm; trunk straight, (180–)220–500(–580) µm (av. 390 µm) long, (8–)10–16(–20) µm wide (n = 16). Ultimate branchlets mostly in pairs, curved to sigmoid, (6.8–)9.1–11.3–13.6(–17.9) µm long, (1.2–)1.4–1.8–2.2(–2.9) µm wide at the base; tip obtuse or subtruncate (n = 30). Conidia hyaline, subglobose, 23–29 µm (av. 26), long, 21–28 µm (av. 24) wide, a length to width ratio of 1.02–1.19 (av. 1.09), (n = 30), the greatest width at median, with a rounded tip and base; pedicel mostly absent, but rarely present as a scar. Resting organs not seen. |
| Notes |
This species was originally described as Peronospora nasturtii-montani on Rorippa indica (= Nasturtium montanum). Molecular phylogenetic analyses of Korean collections confirmed a distinct lineage associated with R. indica, and the species was transferred to Hyaloperonospora by Lee et al. (2017). The Korean collections also represented the first confirmed record of this species in Korea. |
| Economic importance |
No economic losses caused by H. nasturtii-montani have been reported. Its host, Rorippa indica, is primarily a wild brassicaceous plant, although it is also used locally for food and medicinal purposes. |
| References |
Farr, D. F., and Rossman, A. Y. 2026. Fungal Databases, U.S. National Fungus Collections, ARS, USDA.
Gäumann, E. A. 1918. Beih. Bot. Centralbl. 35:395.
Lee, J. S., et al. 2017. Mycobiology 45:139. |
