Arthonia xanthoparmeliarum Etayo

in Etayo & Sancho, Bibl. Lichenol., 98: 49, 2008.
Distribution: S - Si (Brackel & Puntillo 2023).
Description: Thallus inapparent, not lichenized, the hyphae developing inside the thallus and soralia of Xanthoparmelia-species, causing 0.7-1.5 mm wide necrotic patches delimited by a blackish line. Apothecia arthonioid, immersed in the thallus and soralia of the host, more or less round, 1.5-3 mm across, with a black, convex disc, without a distinct proper margin. Proper exciple poorly developed, not evident; epithecium brown, c. 10 µm high; hymenium colourless to pale brown, 35-40 µm high, I+ red, K/I+ blue; paraphysoids branched, the apical cells enlarged, to 3 µm wide; hypothecium pale brown, c. 50 µm high. Asci 8-spored, broadly clavate to subglobose, semi-fissitunicate, with a large, non-amyloid apical dome, and a distinct ocular chamber, Arthonia-type. Ascospores 1-septate, hyaline, claviform, with more or less equal cells or sometimes with the lower cell narrower, 10-14.5 x 4-5 µm, with a hyaline, amyloid perispore. Photobiont absent. Spot tests: K-, C-, KC-, P-. Chemistry: without lichen substances.
Note: a rarely collected species, known from both Americas and Luxembourg; there is an unpublished record from Italy (Sicily, herb. Brackel).
Growth form: Lichenicolous fungus
Substrata: rocks
Reproductive strategy: mainly sexual
paras Xanthoparmelia-species

Commonnes-rarity: (info)

Alpine belt: absent
Subalpine belt: absent
Oromediterranean belt: absent
Montane belt: absent
Submediterranean belt: extremely rare
Padanian area: absent
Humid submediterranean belt: extremely rare
Humid mediterranean belt: extremely rare
Dry mediterranean belt: extremely rare

pH of the substrata:


Solar irradiation:








Altitudinal distribution:


Predictive model
Herbarium samples

University of California, Riverside Lichens (in transfer to SBBG) (UCR(temp):In transfer) - Determiner: Jana Kocourková (2007) Collector: Jana Kocourková Number: 909669 Date: 2007-07-23 Additional Collectors: Kerry Knudsen Locality: United States, California, Riverside, San Jacinto Mountains, near Sugarloaf Mountain 33.58389 -116.43694 Habitat: On crumbling granite boulder. On Xanthoparmelia mexicana. Substrate: Pinyon pines, Yucca sp. - CC BY-NC 3.0 - Source: Consortium of Lichen Herbaria (2023) http// Accessed on December 15.