Megalospora pachycarpa (Duby) H. Olivier

Exp. Syst. Descr. Lich. Ouest Fr., 2: 41, 1900. Basionym: Patellaria pachycarpa Delise ex Duby - Bot. Gall., 2nd ed.: 655, 1830.
Synonyms: Bacidia tuberculosa auct. non (Fée) Trevis.; Bombyliospora incana A.L. Sm.; Bombyliospora pachycarpa (Delise ex Duby) A. Massal.; Bombyliospora tuberculosa auct. non (Fée) A. Massal.; Megalospora tuberculosa auct. non (Fée) Sipman
Distribution: N - Frl. C - Tosc.
Description: Thallus crustose to subleprose, episubstratic, up to 0.2 mm thick, dull, yellowish white, pale grey-greenish or grey-white, not tuberculate, sorediate, forming large patches, without a distinct prothallus. Soralia at first more or less discrete, but soon becoming confluent, forming a more or less continuous sorediate crust; soredia fine to coarse, usually aggregated into up to 80 µm wide consoredia, often with needle-like projecting crystals. Apothecia very rare, rounded, (0.5-)1-2 mm across, with a concave to flat, dark brown disc and a paler or concolorous, raised, persistent proper margin. Proper exciple of radiating hyphae, compact in outer part, loose-arachnoid within; epithecium orange-brown, densely inspersed with granules not dissolving in K; hymenium colourless, 130-180 μm high, inspersed with oil droplets; paraphyses sparingly branched and anastomosing, slightly swollen at tips; hypothecium colourless. Asci 1-spored, clavate-subcylindrical, with a thick amyloid tholus and a I+ blue gelatinous outer layer. Ascospores 5-11-septate, hyaline, 70-160 x 25-35 µm, the wall c. 2 μm thick. Conidia short-bacilliform. Photobiont chlorococcoid (Dictyochloropsis), the cells 5-14 μm wide. Spot tests: thallus: K+ pale yellow, C-, KC+ yellow, P-, UV-. Chemistry: usnic acid, zeorin, unknown terpenoids.
Note: a mainly pantropical species found on old deciduous (mainly Fagus) and coniferous (mainly Abies) trees in humid montane forests, sometimes overgrowing epiphytic bryophytes. It is included in the Italian red list of epiphytic lichens as “Critically Endangered” (Nascimbene & al. 2013c).
Growth form: Crustose
Substrata: bark
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly asexual, by soredia, or soredia-like structures (e.g. blastidia)
Restricted to humid-warm, oceanic areas

Commonnes-rarity: (info)

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

pH of the substrata:


Solar irradiation:








Altitudinal distribution:


Predictive model

Einar Timdal - Source: CC BY-NC

Zahlbruckner A. 1926. Lichenes (Flechten). In: Engler A. (ed.): Die natürlichen Pflanzenfamilien. 2nd ed., vol 8, W. Engelmann, Leipzig, 270 pp.

Einar Timdal - Source: - CC BY-NC