Keys to the macrolichens and checklist of the lichens and ...

8a. Isidia present ............................................................................................................ 9
8b. Isidia absent ........................................................................................................... 11
9a. Lobes narrow, tightly adnate, 0.3-1.0 mm wide .................................. R. amphithrix
9b. Lobes broader, adnate, 1-3.5 mm wide.................................................................. 10
10a. Thallus coriaceous; apothecia ecoronate ............................................ R. planiuscula
10b. Thallus fragile; apothecia subcoronate ............................................. R. schizospatha
11a. Lobes narrow, tightly adnate, 0.3-1.5 mm wide .................................................... 12
11b. Lobes broader, adnate, 1-3.5 mm wide.................................................................. 13
12a. Medulla P+ yellow or orange, containing echinocarpic acid....................R. palmata
12b. Medulla P-, containing relicinulinic acids A, B..................................... R. relicinula
13a. Medulla P+ yellow or orange; containing echinocarpic acid, ±gyrophoric acid
(trace) ...................................................................................................R. gemmulosa
13b. Medulla P-, C+ rose; containing gyrophoric acid (major), echinocarpic acid absent
..............................................................................................................R. luteoviridis
14a. Lower surface pale brown to dark brown .............................................................. 15
14b. Lower surface black, rarely brown-black at lobe margins..................................... 17
15a. Medulla P-; containing barbatic acid .................................................. R. agglutinata
15b. Medulla P+ red-orange; containing protocetraric, fumarprotocetraric or
succinprotocetraric acids........................................................................................ 16
16a. Spores small, ca. 3 x 2 µm; containing succinprotocetraric acid major),
himarprotocetraric acid (minor).........................................................R. ramosissima
16b. Spores larger; containing protocetraric acid (major) .............................. R. sublanea
17a. Apothecia present, coronate or subcoronate .......................................................... 18
17b. Apothecia ecoronate or absent............................................................................... 23
18a. Medulla K+ yellow then red; containing norstictic acid.................... R. subabstrusa
18b. Medulla K- or K+ yellow; norstictic acid absent................................................... 19
19a. Lobes broad, 1-3 mm wide; adnate; containing gyrophoric acid (major).
............................................................................................................R. retrospinosa
19b. Lobes narrow, 0.3-1.5 mm wide; tightly adnate; gyrophoric acid absent or present
in traces only.......................................................................................................... 20
20a. Medulla P-.............................................................................................................. 21
20b. Medulla P+ yellow, orange or red ......................................................................... 22
21a. Hirtifructic acid present ............................................................................ R. fijiensis
21b. Hirtifructic acid absent........................................................................... R. relicinula
22a. Lobes separate, axils broad; with gyrophoric and echinocarpic acid ... R. samoensis