Parmelinopsis

Parmelia dissecta

Parmelia dissecta Nylander, 1882, p. 451.

P. laevigata var. gracilis f. furfuracea Müller-Argau, 1888b, p. 529. [Type collection: Hambi, near Faxina, Brazil, Puiggari 47 (G, holotype).]

P. minarum Vainio, 1890, p. 48. [Type collection: Sitio, Minas Gerais, Brazil, Vainio, Lichenes Brasilienses Exsiccati 1040 (TUR, Vainio Herbarium 2689, holotype; BM, FH, UPS, isotypes).]

P. amazonica var. husnotii Hue, 1899, p. 158. [Type collection: Martinique and Guadeloupe, Husnot 441 (P, holotype).]

P. puiggari Gyelnik, 1931, p. 288. [Based on P. laevigata var. gracilis f. furfuracea Müller-Argau.]

P. camtschadalis var. epiphylla Cengia Sambo, 1938, p. 379. [Type collection: Mufindi, Tanganyika, Balbo 43 (FI, holotype).]

P. hubrichtii Berry, 1941, p. 102. [Type collection: 1.4 mi. north of Jarvis Store, Knox Co., Kentucky, Hubricht 13305 (MO, holotype).]

TYPE COLLECTION.—Fontainebleau, France, Nylander (H, Nylander Herbarium 35131, holotype).

DESCRIPTION.—Thallus adnate, 3–8 cm broad; greenish mineral gray; lobes sublinear to irregular, 2–4 mm wide; marginal cilia distinct, 0.3–0.7 mm long; upper surface plane and continuous, moderately to densely isidiate, the isidia cylindrical, erect, simple to branched, up to 0.5 mm high; lower surface moderately rhizinate, the rhizines simple or in part sparsely furcate. Apothecia adnate, 1–3 mm in diameter, the amphithecium isidiate; spores 8–10×12–17μ.

CHEMISTRY.—Cortex K+ yellow (atranorin); medulla K–, C+ , KC+ rose, P– (gyrophoric acid).

WORLD DISTRIBUTION AND HABITATS.—Pantemperate and pantropical montane; on rocks, conifers, and hardwoods.

Parmelia dissecta, first described from France, was never well understood by most lichenologists who saw it from the tropics, although Vainio correctly identified several specimens from Dominica. There is considerable variation in lobe width, the Dominican material for example being quite robust. Other specimens will have very narrow lobes (about 1 mm wide), but the unifying characters, marginal cilia, isidia, and the C+ color reaction, seem to encompass a single population throughout the wide geographic range. A close relative, P. horrescens Taylor, does not occur on Dominica; it has an almost identical range but differs in chemistry (a KC+ unknown that is also present in P. subfatiscens) and in having more or less flattened to lobulate isidia, some with apical cilia. In the West Indies P. horrescens usually occurs on pine trees at high elevation.

SPECIMENS EXAMINED.—Girondelle, Elliott 1584, Roseau Valley, Elliott s.n., and Shawford Estate, Elliott 1592 (TUR). Hale collections: 13 (35604), 14 (35569), 18 (35593), 20 (35462, 35480, 35486, 35505), and 21 (35356).