“Almond Lichens”: {Amygdalaria sp.}

Names: Amygdalaria, Almond Lichens

Identification Characteristics

Description: Crustose lichens, most often with a thick, areolate thallus; exiple brown-black; asci Porpidia-type

Color: Pinkish or brownish to creamy tones.

Cephalodia: Almost always present containing one of several types of cyanobacteria, sometimes on the same thallus.

Photobiont: Main one is green (unicellular).

Apothecia: Contains black, immersed disks, like Aspicilia.

Spores: Large, almond-shaped, halonate.

Chemistry: Gyrophoric acid & the stictic acid complex are the most common.

Substrate: On siliceous rocks.

Habitat: Mainly humid, oceanic habitats; some are arctic.

Lookalikes: Amygdalaria is distinguished from Porpidia mainly in having cephalodia, larger spores with a compact, conspicuous halo, & more often immersed apothecia.  It is also associated with humid, oceanic habitats.  Related genera with Porpidia-type asci, halonate spores, & immersed apothecia include Bellemerea Immersaria, both of which lack cephalodia.   Bellemerea has brown apothecial disks, a colorless exciple, & smaller spores.  Immersaria carbonoidea is a rare lichen from arctic Alaska with a dark brown, arcolate thallus, black apothecial disks often clustered in groups, a brown epihymenium, & a dark brown hypothecium & exciple.  Its spores are 13 – 13 x 6.5 – 7.5 um, & the thallus mudulla is PD-, K-, C-, IKI+ blue.

Bibliography: Lichens of North America, by Brodo, Sharnoff, & Sharnoff

Database Entry:  Distance Everheart 12-26-13

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