Valsalnicola oxystoma - Fungal Planet

148 Persoonia – Volume 29, 2012 

Valsalnicola oxystoma 

a 

b 

c 

d 

e

Fungal Planet description sheets 

149 

Fungal Planet 128 – 20 December 2012 

Valsalnicola D.M. Walker & Rossman, gen. nov. 

Etymology. Named for its valsa-like appearance and occurrence on 

species of Alnus. 

Causing linear cankers and lesions. Ectostromata well-developed, 

brown to black, thick disc from which perithecial necks 

emerge. Ascomata perithecial, immersed beneath ectostroma, 

aggregated in groups of 13–23, converging into 5–20 necks. 

Asci fusiform, with indistinct apical ring. Ascospores allantoid 

with rounded ends, 1-septate, hyaline. 

Type species. Valsalnicola oxystoma. 

MycoBank MB801277. 

Valsalnicola oxystoma (Rehm) D.M. Walker & Rossman, comb. nov. 

Basionym. Valsa oxystoma Rehm, Ber. Naturhist. Vereins Augsburg 26: 

70. 1881. 

≡ Cryptodiaporthe oxystoma (Rehm) Z. Urb., Preslia 29: 395. 1957. 

Twig lesions in surface view (511–)591–890(–893) µm diam 

(mean = 654, S.D. 122, n = 13). Ectostroma well-developed, 

brown to black, thick disc from which perithecial necks emerge. 

Ascomatal cavity (690–)765–909(–950) µm high × (1610– 

)1710–2346(–3947) µm diam (mean = 816 × 2198, S.D. 109, 

703, n1 = 5, n2 = 9). Ascomata perithecial, immersed beneath 

ectostroma, causing host tissue to swell and rupture, perithecia 

converging into 5–20 necks, emerging at surface through 

ecto stromatic disc, perithecia grouped 13–23. Ascomata 

glossy black, subglobose to globose (240–)266–298(–320) 

µm high × (253–)260–335(–337) µm diam (mean = 282 × 294, 

S.D. 25, 36, n1 = 7, n2 = 13); necks central, straight to curved, 

length (426–)428–550(–563) µm (mean = 476, S.D. 54, 

n = 9). Asci fusiform, (38–)39–48(–49) × (8–)9–12(–13) µm 

(mean = 44 × 11, S.D. 4, 1.2, n1 = 17, n2 = 18), apex broadly 

rounded, with indistinct apical ring, stipe acute, rounded, or tapering 

to a point, ascospores arranged irregularly multiseriate. 

Ascospores allantoid with rounded ends, mostly curved, rarely 

straight, (9–)10–11(–12) × 2–3 µm (mean = 11 × 2, S.D. 0.9, 

0.5, n = 30), 1-septate, median, slightly constricted or not at 

septum, each cell with several small guttules, hyaline. Cultures 

slow-growing, 3–6 mm in 10 d on potato-dextrose agar, mycelium 

low, pale brown to greyish brown, reverse dark brown. 

In culture on synthetic nutrient-poor agar — Dimorphic, 

forming a synanamorph. Conidiomata pycnidial, exuding 

masses of brown conidia. Conidiophores reduced to conidiogenous 

cells, or one supporting cell, proliferating percurrently. 

Conidia cylindrical, brown, finely verruculose, apex obtuse, 

base truncate, 3–5-euseptate, 15–23 × 4–5 µm. Conidia of 

synanamorph intermingled in same conidioma, but conidiogenous 

cells proliferating percurrently or sympodially; conidia 

hyaline to subhyaline, narrowly obclavate, apex subobtuse, 

base truncate, straight to curved, 25–80 × 2.5–3 µm, up to 

11-septate. Synanamorph also developing in aerial mycelium 

(on PNA); conidiophores subcylindrical, straight to curved, 

0–2-septate, hyaline to subhyaline, 8–15 × 2–3 µm, proliferating 

sympodially at apex. Conidiophores solitary or fasciculate 

or on a reduced stroma. 

Colour illustrations. Italy, Trentino, Val Sadole, showing trees of Alnus 

viridis with green alder decline (Giorgio Maresi). a. Rehm: Ascomyceten 280, 

scale bar = 500 µm. b–d. BPI 884137, scale bars of perithecia = 100 µm, 

scale bar of ascus = 10 µm. e. Rehm: Ascomyceten 280, scale bar = 10 µm. 

Typus. Austria, Tyrol, Längenfeld, on dead branch of Alnus viridis, 

c. 3 500 ft., Aug. 1874, coll. Rehm. This type specimen was issued as 

Rehm, Ascomyceten no. 280. Of the two specimens at BPI, the more plentiful 

one is in the bound set of Rehm, Ascomyceten, and is herein designated 

as Lectotype BPI 884138. Isolectotypes examined BPI 738235 and NY, 

MycoBank MB801277. 

Additional specimens examined. Belgium, Brussels, Soignes, on branch 

of Alnus glutinosa, Oct. 1899, P. Nypels, comm. H. Rehm, Vestergren, 

Micro mycetes rariores selecti 409 as Valsa oxystoma (BPI 574854). – Canada, 

British Columbia, Yoho National Park, Chancellor Mountain Camp, on 

Alnus sp., 11 Aug. 1962, R.F. Cain, TRTC 40116 (NY); Ontario, Kenora 

District, Tustin Township, Gordon Lake, Rd., on Alnus sp., 26 Sept. 1959, 

coll. D. Bowen, det. J. Reid as Valsa oxystoma (BPI 574855). – Italy, Trento, 

Monte Bondone Trento, E11°03'51" N46°02'20", on Alnus viridis, Apr. 

2011, G. Maresi, isol. A. Rossman AR 4833 = CBS 133337, ITS sequence 

JX519559, and LSU sequence JX519563 (BPI 884137); Trento, val Sadole 

(E11.60, N46.15), 2009, G. Maresi & C.M.O. Longa (BPI 884136). – Sweden, 

Umea, on dead branch of Alnus ‘borealis’, Sept. 1910, Vlengel, det. 

F. Bubak (BPI 574856). – USA, Alaska, near Fairbanks, Moose Creek, Environmental 

Monitoring Plot 316 MC UM11 MRC, N64.72, W147.23, elev. 

150 m, on Alnus incana var. tenuifolia, May 2010, G.C. Adams, culture AR 

5137 = CBS 133329, ITS sequence JX519561 (BPI 884135). 

Habitat — Alnus viridis ssp. viridis, causing a twig colonization 

and canker disease involved in green alder decline (Pisetta 

et al. 2012); also known from Alnus glutinosa, A. incana, 

A. incana var. tenuifolia, A. rubra, A. viridis ssp. fruticosa and 

A. viridis ssp. maximowiczii. 

Distribution — Asia: Japan (Kobayashi 2007); Europe: Austria, 

Belgium, Italy, Sweden, also United Kingdom (Cannon et 

al. 1985); North America: Canada (Ontario); USA: Alaska. 

Notes — Valsalnicola is based on a species that was described 

in the genus Valsa. Although it resembles Valsa in 

having allantoid ascospores, the ascospores of Valsalnicola 

are 1-septate while the majority of species of Valsa and closely 

related Leucostoma and Valsella have aseptate ascospores. 

However, one species of Valsa, V. melanodiscus, also has 

1-septate ascospores, occurs on Alnus spp., and produces linear 

cankers on the host. A distinguishing feature of Valsalnicola 

is the lack of a black line surrounding stromata in the ascomatal 

cavity, which is characteristic of Valsa melanodiscus. In 

addition, the growth rate of cultures of Valsalnicola oxystoma 

is considerably slower than species of Valsa. Molecular sequence 

data place this new genus within the Gnomoniaceae- 

Melanconidaceae complex. Allantoid, 1-septate ascospores 

have not previously been reported in the Gnomoniaceae or 

Melanconidiaceae. ITS sequences of specimens from Alaska 

and Italy are identical. The basionym has been cited as Rehm: 

Ascomyceten 270 (1875) in ‘Index Fungorum’ reflecting an error 

in Saccardo (1882) but the correct number is Rehm: Ascomyceten 

280, which does not include a description. 

Donald M. Walker, Department of Natural Sciences, The University of Findlay, Findlay, OH 45840, USA; e-mail: walkerd@findlay.edu 

Amy Y. Rossman, Systematic Mycology & Microbiology Laboratory, USDA-ARS, Beltsville, MD 20705, USA; e-mail: Amy.Rossman@ars.usda.gov 

Gerard C. Adams, Department of Plant Pathology, University of Nebraska, Lincoln, NE 68583, USA; e-mail: gadams3@unl.edu 

Claudia Maria Oliveira Longa, FEM-IASMA - Research and Innovation Centre, Sustainable Agro-Ecosystems and Bioresources Department. Via E. Mach 1, 

38010 San Michele all’Adige (TN), Italy; e-mail: claudia.longa@fmach.it 

Giorgio Maresi, IASMA - Centre for Technology Transfer, Via E. Mach 1, 38010 San Michele all’Adige (TN), Italy; e-mail: giorgio.maresi@fmach.it 

© 2012 Nationaal Herbarium Nederland & Centraalbureau voor Schimmelcultures

Valsalnicola oxystoma - Fungal Planet

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