TYPE. BRAZIL. “Crescit in ramulis arborum ad ripam fluvii Amazonum.” [on tree branches along banks of the Amazon River] (Martius 1833).

Life form. Lichenized fungus.

Description. Thallus fruticose, yellow-green, branches up to 3-4 cm. long, but more often smaller; branches 5 mm wide, dichotomous, compressed, becoming grooved, channels shallow, disappearing toward the tips; surface shiny, papillate; cortex thick, cartilaginous to soft in old specimens, thin in young thalli. Ascomata lecanorine apothecia, frequent, usually terminal with short subtending branches, adnate, 2-5 mm diam., variable in size in accordance with the size of the lichens; disk concave, rarely convex, tan colored, pruinose; margin rugose to denticulate. Asci 8-spore; ascospores 2-celled, ellipsoid or ellipsoid-elongate, curved, or bent, variable, 9-16 x 4-9um.

Chemistry. Medulla K+ red, PD-, KC-; salazinic acid detected by TLC.

Substrate and habitat. Corticolous on hardwood trees and shrubs along the coast and inland coast, especially in undisturbed habitats.

Distribution. Gulf and Atlantic coasts of southeastern North America; in North Carolina found in the Coastal Plain ecoregion.

Note. Ramalina denticulata is morphologically similar to R. complanata except for its narrower branches as well as its chemistry (Howe 1914; S.A. LaGreca, pers. comm., 3 Mar 2024).

Literature

Howe., R.H., Jr. (1914) North American species of the genus Ramalina. Part V. The Bryologist 17(3): 33-40.

Landrón Concepción, I. 1972. The lichen genus Ramalina Ach. in the West Indies with notes on its role in the vegetation of Puerto Rico. Ph.D. Thesis. Michigan State University. xiv+342pp.

Malme, G.O.A. (1934) Die Ramalinen der ersten Regnellschen Expedition. Arkiv för Botanik 26A, Nr. 12: 1-9.

Martius, C.F.P. von (1833) Flora Brasiliensis seu enumeratio plantarum. 1: 1-390 (original description as Parmelia reticulata).