Gymnosporangium paraphysatum Vienn. -Bourg., Revue de Mycologie (Paris) 25 (5): 304 (1961)
Index Fungorum number: IF 331602; Mycobank number: MB 331602; Facesoffungi number: FoF Fig. 1
Holotype – BPI 844997.
Parasitic on leaves of Calocedrus formosana. Sexual morph: Not observed. Asexual morph: Uredinia foliicolous, amphigenous, solitary and scattered, 0.2–0.6 mm across, subepidermal, becoming erumpent, surrounded by discolored margins. Paraphyses numerous, intermixed, stalks hyaline, filiform, 117–172 μm long, 2.5–5 μm wide, apex brown, clavate, 38–58 ×16–25 μm. Urediniospores orange to yellowish, broadly ellipsoidal to oval, 28–43×16–22 μm, tapered towards the apex, wall hyaline, 1.2–2.5 μm, thickened at the apex, 2–8 μm.
Material examined – Taipei, Taichung City, Dongshi District, Tungshih Forestry Station, on leaves of Calocedrus formosana, 21 Apr 2016, Yuan-Min Shen (TNM F0030451)
GenBank numbers – SSU-ITS-LSU: PP923925.
Notes – The rust produces urediniospores and teliospores on leaves of Calocedrus but has no known spermogonial and aecial stages. It is characterized by the presence of numerous conspicuous paraphyses (Kern 1973). The type specimen of this species was collected from the host plant Calocedrus macrolepis (Libocedrus macrolepis) in Vietnam. Although Hiratsuka & Chen (1991) listed the fungus on C. formosana, no characterization of the rust on this host had been made. This note provides the first description of G. paraphysatum on C. formosana and represents the first confirmed report of G. paraphysatum. New sequence data have been generated based on our collection. The species may be closely related to G. libocedri due to the phylogenetic relationship and their ability to parasitize the plant genus Calocedrus (Kern 1973; Kasuya et al. 2024).
Figure 1 – Gymnosporangium paraphysatum (TNM F0030451). a Collection of the specimen on Calocedrus formosana in the field. b, c Uredinia and urediniospores on the leaves. d Urediniospores. e Paraphyses. Scale bars: b=2 mm, c=0.5 mm, d, e=20 µm