Ramalina subfraxinea Nylander var. subfraxinea

Marcano, Vicente, Méndez, Antonio Morales & Prü, Ernesto Palacios, 2021, The genus Ramalina Acharius (Ascomycota, Lecanoromycetes, Ramalinaceae) in northern South America, Phytotaxa 504 (1), pp. 1-77 : 60

4. Ramalina subfraxinea Nylander var. subfraxinea

Bull. Soc. Linn. Normandie II, 4: 139 (1870) . Type :― COLOMBIA. Turbaco : Nova Granata, 1844, Goudot s.n (lectotype PC, isotype H).

Thallus corticolous, erect or more or less pendulous, greenish, dichotomously branched, 2–5 cm long. Branches solid, canaliculate, surface subshiny, smooth, 0.5–1(–3.5) mm wide. Pseudocyphellae ellipsoid, laminal, present in the lower side, 200–500 μm long. Soralia not seen. Cortical tissue 10–12 μm thick. Peripheral chondroid tissue 70–80 um thick. Medulla dense. Pycnidia not seen. Apothecia numerous, marginal, subapical, disc concave, plane or convex, 3–4 mm in diameter, margin entire. Ascospores 1–septate, colorless, straight to curved, 11–12 x 5–6 µm.

Chemistry (TLC, HPTLC): Strain 1. Divaricatic, boninic, 2ˊ– O –methylsekikaic (tr.) and protocetraric acids (Sipman & Reyes 34455). Strain 2. Sekikaic and homosekikaic acids (Cleef & Jaramillo 4190–A). Strain 3. Sekikaic acid (Sipman & Reyes 34400). Strain 4. Divaricatic, ramalinolic and salazinic acids (Steyermark & Davidse 116542).

Ecology and distribution: This taxon is found growing on shrubs and trees in dry habitats, pastures and rainforests at 2750–2950 m. In Colombia it occurs on Xylosma trunks in Weinmannia , Xylosma and Vallea forests. It is known from northern South America ( Colombia and Venezuela), India and Australia.

Remarks: Ramalina subfraxinea could be confused with R. africana and R. complanata . But both of the latter species have tuberculate pseudocyphellae. Additionally, R. subfraxinea is much larger than R. complanata . Further, R. africana has spurred apothecia and long ellipsoid spores (12–15 x 3–5 µm). Ramalina subfraxinea var. subfraxinea from Colombia and Venezuela exhibits four distinct chemical strains, with divaricatic acid or sekikaic acid and its aggregates as major medullary substances. Stevens (1987) recognized four chemical races as varieties in R. subfraxinea from Australia: var. subfraxinea , containing sekikaic or divaricatic acids; var. leoidea ( Nylander 1870: 141) N. Stevens (1987: 207) , containing boninic acid; var. confirmata ( Nylander 1870: 138) N. Stevens (1987: 205) , containing cryptochlorophaeic acid and var. norsticitica N. Stevens (1987: 208) , with norstictic acid ( Stevens 1987). In northern South America R. subfraxinea var. subfraxinea strain 1 contained a mixture of divaricatic ( var. subfraxinea ) and boninic acids ( var. leoidea ).

Specimens examined: COLOMBIA: Boyaca: Municipio Arcabuco, c 15 km on the road towards Tunja , 2900 m, 11 July 1986, H . Sipman & O . Reyes 34400 ( B) . Cundinamarca: Represa del Neusa, Valle Rio Neusa, c. 3 km S Represa , 2750 m, 26 May 1972, A . Cleef & R . Jaramillo 4190 ( B) . Boyaca: Municipio Cucaita, c. 10 km W of Tunja alonf road to Villa de Leiva , 2950 m, 12 July 1986, H . Sipman & O Reyes 34455 ( B) . VENEZUELA: Miranda: Cerros del Bachiller, near east end, between base and summit, above Quebrada Corozal , 20–700 m, 20–26 March 1978, J. A . Steyermark & G . Davidse 116542 ( MO, VEN) .