Thelidium fontigenum A. Massal.

Miscell. Lichenol.: 31, 1851.
Synonyms: Involucrothele cataractarum (Hepp) Servít; Sagedia cataractarum Hepp; Thelidium cataractarum (Hepp) Lönnr.
Distribution: N - Ven, Piem, VA (Piervittori & Isocrono 1999).
Description: Thallus crustose, hemiendosubstratic to thinly episubstratic, continuous or forming small flecks, white, whitish grey, greyish green, rarely with yellowish to reddish, K+ violet patches, 45-145 μm thick, proso- to paraplectenchymatous. Cortex not differentiated, but uppermost 10-15 μm of thallus sometimes yellowish brown. Perithecia black, 0.2-0.3 mm across, immersed to semi-immersed in the thallus, the basal part sometimes immersed also in the rock, the projecting part naked. Involucrellum absent or apical to almost reaching the thallus base, thin (10-35 μm), adpressed to exciple or laterally extending in the thallus; exciple 160–340 μm across, colourless to black-brown in lower part; hamathecium of periphyses and periphysoids, interascal filaments absent; periphyses up to 30 μm long; hymenial gel I+ red (I+ blue at very low concentrations of I), K/I+ blue. Asci 8-spored, ellipsoid to clavate, c. 60 x 20 μm, I-, fissitunicate, the wall thickened above, with an ocular chamber, dehiscent by extrusion of a delicate rostrum. Ascospores(1-)3-septate, hyaline, ellipsoid. (20-)27-36(-47) x (9-)11-14(-17) μm. Photobiont chlorococcoid. Spot tests: all negative, except the pigmented patches which react K+ purple. Chemistry: a quinone-like pigment in thallus.
Note: on limestone, dolomite, calcareous sandstone, near creeks and waterfalls in upland areas, but usually below treeline.
Growth form: Crustose
Substrata: rocks
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly sexual

Commonnes-rarity: (info)

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

pH of the substrata:

12345

(info)

Solar irradiation:

12345

(info)

Aridity:

12345

(info)

Eutrophication:

12345

(info)

Poleotolerance:

0123

(info)

Altitudinal distribution:

123456

(info)


Predictive model
Index Fungorum GBIF

Source: https://fungi.myspecies.info/all-fungi/thelidium-fontigenum - Photo uploaed by Paul Cannon CC BY NC
Thelidium fontigenum, ascomata on calcareous sandstone, VC77 Lanarkshire.


Robert F. Hoover Herbarium, Cal Poly State University - Public Domain; Owner: Source:http://lichenportal.org/portal/collections/individual/index.php?occid=3023376


Source: https://fungi.myspecies.info/all-fungi/thelidium-fontigenum - Photo uploaed by Paul Cannon CC BY NC
Thelidium fontigenum, ascospores. Collection from calcareous sandstone, VC77 Lanarkshire.