Lecidella asema (Nyl.) Knoph & Hertel var. asema

Bibl. Lichenol., 36: 66, 1990. Basionym: Lecidea asema Nyl. - Flora, 55: 356, 1872.
Synonyms: Lecidea distrata Arnold non Nyl.; Lecidea distratula Zahlbr.; Lecidea latypea auct. p.p. non Ach.; Lecidea polyantha Taylor ex Leight.; Lecidea subincongrua Nyl.; Lecidella subincongrua (Nyl.) Hertel & Leuckert
Distribution: N - VG, Frl (Tretiach & Hafellner 2000), TAA (Arnold Lich. Exs. 941a, Orom: Knoph & Leuckert 1994, Caniglia & al. 2002), Lomb (Valcuvia 2002, 2002b), Piem (Morisi & Sereno 1995, Valcuvia 2002, 2002b), VA (Piervittori & al. 2004), Lig (Brunialti & al. 1999). C - Tosc (Pišút 1997), Umb (Ravera & al. 2006, 2006b, Genovesi 2011), Laz (Genovesi & al. 2011), Abr (Nimis & Tretiach 1999), Sar (Nöske 2000, Rizzi & al. 2011, Giordani & al. 2013, Neuwirth 2018). S - Camp (Garofalo & al. 1999), Pugl (Nimis & Tretiach 1999), Bas (Nimis & Tretiach 1999), Cal (Puntillo 1996), Si (Nimis & al. 1996b, Grillo & al. 1996, Grillo 1998, Grillo & Caniglia 2004, Cataldo & Cannavò 2014).
Description: Thallus crustose, episubstratic, very thin to very thick (0.1-1.8 mm), strongly rimose to areolate-granulose, the areoles contiguous or dispersed, flat to usually convex, white, to greyish white. Cortex overlain by a 10-20 µm thick epincecral layer; medulla white, I-. Apothecia lecideine, black, shiny at least when young, sessile and strongly constricted at base, 0.5-1.2(-1.5) mm across, with a flat to convex disc and a usually persistent proper margin (older apothecia may be immarginate). Proper exciple grey-green to brownish-green in outer part, pale brown within, with crystals dissolving in K; epithecium blackish green to bluish green, rarely olive-brown in old apothecia, 10-15 µm high, N+ red; hymenium colourless, not inspersed with oil droplets, with granules dissolving in K, 65-95 µm high; paraphyses easily made free in K, simple, rarely anastomosing or branched, c. 2 µm thick at mid-level, the apical cells up to 4 µm wide; hypothecium pale reddish brown. Asci 8-spored, clavate, with an intensely I+ blue tholus penetrated by a weakly amyloid, broadly cylindrical axial mass, and a poorly developed ocular chamber, Lecidella-type. Ascospores 1-celled, hyaline, ellipsoid, 9-17(-20) x 5.5-9 µm, with a thick, smooth wall, not halonate. Pycnidia globose, black. Conidia thread-like, strongly curved, 20-30 x c. 1 µm. Photobiont chlorococcoid. Spot tests: thallus K- to rarely K+ yellow, C- or C+ yellowish red, KC+ slowly reddish orange, P-. Chemistry: atranorin, chloroatranorin, thiophanic acid, and variable quantities of other xanthones.
Note: a widespread, chemically variable species of basic siliceous rocks, on faces wetted by rain, with a wide altitudinal range.
Growth form: Crustose
Substrata: rocks
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly sexual

Commonnes-rarity: (info)

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

pH of the substrata:


Solar irradiation:








Altitudinal distribution:


Predictive model
Herbarium samples

Harrie Sipman

Einar Timdal - Source: http://nhm2.uio.no/lav/web/index.html - CC BY-NC

Curtis Randall Björk – CC BY-SA 4.0
British Columbia, Vancouver Island, Albert Head Date: 2013-10-08 On rock in aerohaline zone

Nere Sorrentino
Spain, Galicia, Alantic Coast

Harrie Sipman

P.L. Nimis CC BY-SA 4.0
TSB 10234