Siphula (Kantvilas, 2002)

Marcano, Vicente, 2021, The genus Siphula Fr. (Icmadophilaceae, Lichenized Fungi) in Venezuela, Phytotaxa 489 (1), pp. 10-26 : 15

Key to Siphula in Venezuela

1 Thallus shrubby, sparsely branched; medulla C– ........................................................................................................................... (2) Thallus not shrubby, scarcely branched; medulla C+ or C–........................................................................................................... (3)

2 (1) Lobes terete, divided up to 4 times; surface smooth; apices rounded; containing thamnolic acid and siphulin (medulla P+ yellow); Guayana Highlands and northern Brazil......................................................................................................................... S. carassana Lobes flattened, divided 1–3 times; surface verrucose; apices truncate; containing baeomycesic and squamatic acids (medulla P+ yellow-orange); pantropical ( Australia, South America) .................................................................................................. S. fastigiata

3 (1) Lobes flabellate, sinuous, flattened at the base; apices sinuous, shortly time divided; surface pale pink; containing thamnolic and hypothamnolic acids (medulla P+ orange, C–); Chimantá massif, Churí tepui.......................................................... S. chimantensis Lobes not flabellate ......................................................................................................................................................................... (4)

4 (3) Apices truncate or occasionally sinuous; containing squamatic and/or baeomycesic acids (medulla P+ yellow-red, C+ yellow); Chimantá massif, Churí tepui .......................................................................................................................................................... (5) Apices not truncate; containing thamnolic acid as the major compound (medulla P –, C–); Neotropical or Pantropical .............. (6)

5 (4) Apices entire or with cortex disrupted, somewhat rounded, truncate or concave, eroded, radially thickened; lobes very small, simple, unbranched, 1–1.8 mm tall; surface smooth, whitish or yellowish; containing squamatic acid ....................... S. subsimplex Apices mostly truncate, concave, with cortex not disrupted, not eroded; lobes 1.2–2 cm tall; surface ash white; containing squamatic and baeomycesic acids ............................................................................................................................................. S. subpteruloides

6 (4) Lobes up to 4 cm tall; surface longitudinally striate or canaliculate, margins somewhat involute; apices entire, rounded or blunt; Neotropical (northern Andes, Costa Rica)...................................................................................................................... S. pteruloides Lobes 0.4–2 cm tall; surface coriaceous or roughened; apices furcate or irregularly pectinate, thickened; Pantropical (Andes, Guayana, Australasia and southern Africa) .................................................................................................................... S. decumbens