Remototrachyna costaricensis (Nyl.) Divakar & A. Crespo

Parmelia costaricensis

Parmelia costaricensis Nylander in Polakowsky, 1877, p. 225.

P. sublaevigata f. isidiosa Müller-Argau, 1880, p. 267. [Type collection: Petropolis, Brazil, Deventer 49 (G, holotype).]

P. tropica Vainio, 1896, p. 33. [Type collection: Hermitage Woods, St. Vincent, Elliott 276 (BM, lectotpye; TUR, isotype).]

P. tropica var. deformis Vainio, 1896, p. 33. [Type collection: St. Vincent, Elliott 12 (BM, lectotype).]

P. deformis (Vainio) Vainio, 1907, p. 169.

P. amoena Zahlbruckner, 1908, p. 464. [Type collection: Serro do Ouro Preto, Brazil, Damazio 1435 (WU, lectotype; H, isotype).]

TYPE COLLECTION.—Angostura, Costa Rica, Polakowsky (H, Nylander Herbarium 35202, holotype).

DESCRIPTION.—Thallus adnate to loosely attached, whitish mineral gray, 6–10 cm in diameter; lobes sublinear to subirregular, 2–6 mm wide; upper surface plane, usually strongly maculate, moderately isidiate, the isidia simple or branched; lower surface moderately rhizinate, black, the rhizines dichotomously branched. Apothecia rare (not seen in Dominica), adnate, 2–7 mm in diameter; spores 4–6×8–10μ.

CHEMISTRY.—Cortex K+ yellow (atranorin); medulla negative with color reagents (protolichesterinic acid, possibly intermixed with caperatic acid). As with most fatty acid-containing species of Parmelia, the chemistry is not fully elucidated. The present microcrystal tests do not adequately separate fatty acids. In this particular species the feathery crystals from G.E. solution suggest that protolichesterinic acid at least predominates.

WORLD DISTRIBUTION AND HABITATS.—West Indies, Central and South America, Philippines, Indonesia, and Malaysia; on tree trunks and rocks at mid to high elevations (400–3,300 m).

Although Elliott collected some large specimens of P. costaricensis, this seems to be a rare lichen in Dominica. It has rather broad lobes in contrast to the more usual linear-elongate lobes of section Hypotrachyna. Rhizines form a dense mat. Maculae in the upper cortex are usually conspicuous in New World specimens, less so or absent in Asian populations tentatively identified with P. costaricensis. The species is superficially close to P. imbricatula (see under that species) and all isidiate specimens with branched rhizines should be color tested with KC, P. imbricatula being deep KC+ orange.

SPECIMENS EXAMINED.—Shawford Estate, Elliott 1529 (TUR). Hale collection: 14 (35569a).

Hypotrachyna costaricensis

Parmelia costaricensis Nylander in Polakowsky, 1877:225. [Type collection: Angostura, Costa Rica, Polakowsky (H, lectotype).]

Parmelia hypotrachyna Nylander, 1860:405. [Type collection: Tolima, Colombia, Goudot (P, lectotype).]

Parmelia sublaevigata f. isidiosa Müller Argau, 1880:267.

Parmelia tropica Vainio, 1896:33.

Parmelia tropica var. deformis Vainio, 1896:33.

Parmelia deformis (Vainio) Vainio, 1907:169.

Parmelia amoena Zahlbruckner, 1908:464. [For full citations, see Hale, 1971a:ll.]

Thallus adnate to loosely adnate, growing on rocks or trees, whitish to greenish mineral gray, 6–10 cm in diameter; lobes sublinear to irregular, often imbricate, 2–6 mm wide; upper surface plane, usually strongly maculate, moderately isidiate, the isidia cylindrical, erect, simple to branched; lower surface moderately to densely rhizinate, forming a thick mat visible along the margins from above, the rhizines densely dichotomously branched. Apothecia rare, adnate, 2–7 mm in diameter; spores 4μ–6μ × 8μ–10μ.

CHEMISTRY.—Cortex K+ yellow, medulla negative with all reagents (atranorin and protolich-esterinic and possibly caperatic acids).

DISTRIBUTION.—Mexico, Central America, West Indies, Andean region from Venezuela to Bolivia, Brazil, and Southeast Asia.

HABITAT.—On deciduous trees, conifers, palm, rocks, and (rarely) soil, in scrub forests, secondary cloud forests, and coffee plantations at 1000–3500 m elevation.