Norw. J. Bot. 25: 55 (1978).
Protolog: Data lacking.
Protolog type data: The Canary Islands: Fuerteventura; Aceitunal, saxicolous on vertical or overhanging cliffs at 500-685 m altitude. Krog & Østhagen 1252 (O, holotype; BM, TFMC, isotypes).
Type locality: Spain, Canary Islands, Fuerteventura, Aceitunal, saxicolous on vertical or overhanging cliffs, 500 - 685 m, without date, H. Krog & H. Osthagen 1252 (O - holotype, BM, TFMC, UPS - isotypes). TLC: Sekikaic acid.
Type locality coordinates: WGS84 28°32'49.74"N 13°57'30.49"W.
Molecular barcode: Data lacking.
Thallus: fruticose, caespitose, erect to subpendulous, up to 3 cm long, without a distinct, delimited holdfast. Laciniae pale greenish grey to stramineous, subshiny, richly branched, branching predominantly dichotomous, isotomic or anisotomic, branches solid, subterete to terete, 0.1 - 1 mm in diameter, with numerous nodules, tapering apically, surface hard, old branches weakly striate. Dark spots recalling pycnidia fairly common. Soralia absent. Cortex indistinct, chondroid cylinder continuous, coalescing between the nodules, medulla and algal cells restricted to the nodules, between the clumps only chondroid tissue present. Well-developed nodules often cracked, exposing the medulla and then resembling soralia, old nodules sometimes bearing short fibrils. Soralia lacking. Isidia lacking. Pseudocyphellae absent. Apothecia rare, lateral, up to 1.5 mm in diameter, spores 8 - 10 / 2 - 5 µm. Pycnidia unknown (Krog & Østhagen 1978: 55; Krog & Østhagen 1980: 284).
Photobiont: Data lacking.
Chemistry: Unknown R1 (Krog & Swinskow 1974; Krog & Østhagen 1978: 55).
Ecology: Saxicolous, rarely terricolous, or muscicolous (Krog & Østhagen 1978: 55).
Distribution Type: Canary Islands (Fuerteventura, Gomera, Tenerife), Madeira (Main Island and Deserta Grande), as well as Baja California in Mexico [fide CNALH]. From CNALH: Mexico, Baja California Sur, along road to Punta Eugenia, 3 km W of Rte. 1 at Vizcaino Junction, 60 m, 9 January 1989, T. H. Nash 26244, 27.65 -113.4166667.
Taxonomy: Ramalina nodosa is characterised by delicate, thin (0.1-1 mm), richly branched subterete to terete laciniae without soredia and pseudocyphellae, with numerous nodules (Pisut 2009: 183).
Note: Described from Fuerteventura, Gomera and Tenerife (Krog & Østhagen 1980, Aptroot & Schumm 2008), the species was later found on Madeira (Pisut 2009: 183).
Distribution Database: Distributions
Picture Database: Tropical Lichens
Molecular Database: Genbank
Synonym Database: Index Fungorum
Synonym Database: Mycobank
Race I: Sekikaic acid (Krog & Osthagen 1980: 284). Usnic acid in the cortex. (Krog & Osthagen 1980: 284 all samples except one).
Race II: Divaricatic acid (Krog & Osthagen 1980: 284). Usnic acid in the cortex. (Krog & Østhagen 1980: 284 a single specimen from Tenerife).