Nine shrubby Usnea species were documented from East Fennoscandia (Table 1), but a treatment of the pendent species, excluding Usnea longissima, is still under preparation. The whole known Usnea flora of British Columbia was studied and 25 species [U. fulvoreagens (Räsänen) Räsänen included as a separate species]; and species groups were recorded from the province (Table 1). U. chaetophora Stirt., U. diplotypus Vain. and U. nidulans Motyka s. lat. were new to North America, whereas U. esperantiana Clerc and U. rigida s. lat. were documented for the first time for Canada, and U. ceratina and U. rubicunda were new to British Columbia. U. pacificana Halonen was described as a new species from the Pacific Canada and the United States, and U. wasmuthii Räsänen was reported from the states of Washington and Oregon as new to North America (V).
Clerc (1987a) divided the shrubby Fennoscandian Usnea species into six groups (Table 2): U. diplotypus agg., U. fragilescens agg., U. glabrescens agg., U. lapponica agg., U. subfloridana agg. and U. hirta (single species). He did not include U. glabrata (Ach.) Vain. in any of these aggregates, but in the study of the British Columbia Usnea we referred it to the U. fragilescens agg., which also contains U. cornuta Körb. s. lat., U. esperantiana, U. fragilescens Lynge var. mollis (Vain.) Clerc and U. wirthii (IV). There are also many other different views on the systematics of Usnea presented in our studies when compared to Clerc (1987a) (Table 2). For example, Clerc (1987a) regarded U. fulvoreagens as a member of the ”U. lapponica agg.”, but we found it to represent a taxon close to U. glabrescens (Nyl. ex Vain.) Vain. ex Räsänen (III, IV). We included U. fulvoreagens and U. glabrescens in the U. florida agg. together with U. pacificana, U. subfloridana Stirt. and U. wasmuthii (III, V), while U. lapponica belongs to the U. rigida agg. with U. diplotypus, U. rigida s. lat., U. scabrata Nyl. s. lat. and U. substerilis Motyka (III, IV). Usnea hirta and U. longissima cannot be inluded in any of these three aggregates.
Table 1. Main secondary medullary metabolities in the genus Usnea in East Fennoscandia and Pacific North America. The North American data is mainly based on the British Columbia material, except Usnea fulvoreagens and U. wasmuthii (see comments 3 and 4). E-FEN = East Fennoscandia, P-AM = Pacific North America, 1 = the occurrence in East Fennoscandia is not studied, 2 = unpublished data, 3 = the material is mainly from the United States, 4 = all specimens are from the United States, * = the species was not found from East Fennoscandia, + = present in all specimens examined, ± = present in some specimens (chemoraces), a = accessory substance, not important for taxonomy and often present in small amount to faint traces, S = present only in soralia, H = the strain may be a hybrid. ATR = atranorin, BAE = baeomycesic acid, BAR = barbatic a., CNSTI = connorstictic a. (seemingly overlooked in the studied material and it was excluded in IV), Cph-1 = convirensic a., Cph-2 = confumarprotocetraric a., CPSO = 2’-O-demethyl-psoromic a., CRSTI = cryptostictic a., CSTI = constictic a., DBAR = 4-O-demethyl-barbatic a., DIF = diffractaic a., EVE = evernic a., FAT = fatty acids (bourgeanic acid in U. esperantiana, the murolic acid complex in U. hirta and usually caperatic acid in U. lapponica), FUM = fumarprotocetraric a., MEN = menegazziaic a., NSTI = norstictic a., PRO = protocetraric a., PSO = psoromic a., SAL = salazinic a., SQU = squamatic a., STI = stictic a., THA = thamnolic a.
| Area | ATR | EVE | DIF | BAR | DBAR | BAE | SQU | THA | Cph-1 | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1. | Usnea cavernosa | E-FEN | * | * | * | * | * | * | * | * | * | |||
| P-AM | – | – | – | – | – | – | – | – | – | |||||
| 2. | Usnea ceratina | E-FEN | * | * | * | * | * | * | * | * | * | |||
| P-AM | – | – | + | + | a | – | – | – | – | |||||
| 3. | Usnea chaetophora | E-FEN1 | * | * | * | * | * | * | * | * | * | |||
| P-AM | – | – | – | – | – | – | – | – | – | |||||
| 4. | Usnea cornuta s. lat. | E-FEN | * | * | * | * | * | * | * | * | * | |||
| P-AM | – | – | – | – | – | – | – | – | – | |||||
| 5. | Usnea diplotypus | E-FEN | – | – | – | ± | a | – | – | – | – | |||
| P-AM | – | – | – | ± | a | – | – | – | – | |||||
| 6. | Usnea esperantiana | E-FEN | * | * | * | * | * | * | * | * | * | |||
| P-AM | – | – | – | – | – | – | – | – | – | |||||
| 7. | Usnea filipendula s. lat. | E-FEN2 | – | – | – | – | – | – | – | – | – | |||
| P-AM | – | – | – | – | – | – | – | – | – | |||||
| 8. | Usnea fragilescens var. mollis | E-FEN | * | * | * | * | * | * | * | * | * | |||
| P-AM | a | – | – | – | – | – | ± | – | – | |||||
| 9. | Usnea fulvoreagens | E-FEN | – | – | ± | – | – | – | – | – | – | |||
| P-AM2,3 | – | – | – | – | – | – | – | – | – | |||||
| 10. | Usnea glabrata | E-FEN | – | – | – | – | – | – | a | – | a | |||
| P-AM | – | – | – | ± | a | – | – | – | a | |||||
| 11. | Usnea glabrescens | E-FEN | – | – | – | – | – | – | – | – | – | |||
| P-AM | – | – | – | – | – | – | – | – | – | |||||
| 12. | Usnea hesperina | E-FEN | * | * | * | * | * | * | * | * | * | |||
| P-AM | – | – | – | – | – | – | – | – | – | |||||
| 13. | Usnea hirta | E-FEN | – | – | – | – | – | – | – | – | – | |||
| P-AM | – | – | ± | – | – | – | – | – | – | |||||
| 14. | Usnea lapponica | E-FEN | – | – | – | – | – | – | – | – | – | |||
| P-AM | – | – | – | ± | a | – | – | – | – | |||||
| 15. | Usnea longissima | E-FEN | – | – | + | – | – | – | a | – | – | |||
| P-AM | a | ± | ± | ± | a | – | – | – | – | |||||
| 16. | Usnea madeirensis | E-FEN | * | * | * | * | * | * | * | * | * | |||
| P-AM | – | – | – | a | a | – | – | – | – | |||||
| 17. | Usnea nidulans s. lat. | E-FEN | * | * | * | * | * | * | * | * | * | |||
| P-AM | – | – | – | – | – | – | – | – | – | |||||
| 18. | Usnea pacificana | E-FEN | * | * | * | * | * | * | * | * | * | |||
| P-AM | – | – | – | a | a | + | + | – | – | |||||
| 19. | Usnea rigida s. lat. | E-FEN | * | * | * | * | * | * | * | * | * | |||
| P-AM | – | – | – | – | – | – | – | – | – | |||||
| 20. | Usnea rubicunda | E-FEN | * | * | * | * | * | * | * | * | * | |||
| P-AM | – | – | – | – | – | – | – | – | – | |||||
| 21. | Usnea scabrata s. lat. | E-FEN 2 | – | – | – | – | – | – | – | – | – | |||
| P-AM | – | – | – | – | – | – | – | – | – | |||||
| 22. | Usnea subfloridana | E-FEN | – | – | – | – | – | – | ± | ± | – | |||
| P-AM | – | – | – | – | – | – | ± | ± | – | |||||
| 23. | Usnea substerilis | E-FEN | – | – | – | ± | a | – | – | – | – | |||
| P-AM | – | – | – | ± | a | – | – | – | – | |||||
| 24. | Usnea trichodea | E-FEN | * | * | * | * | * | * | * | * | * | |||
| P-AM | – | – | + | – | – | – | – | – | – | |||||
| 25. | Usnea wasmuthii | E-FEN | – | – | – | ± | a | – | – | – | – | |||
| P-AM 4 | – | – | – | + | a | – | – | – | – | |||||
| 26. | Usnea wirthii | E-FEN | * | * | * | * | * | * | * | * | * | |||
| P-AM | – | – | – | – | – | – | – | – | – | |||||
| Area | Cph-2 | FUM | PRO | NSTI | CNSTI | STI | CSTI | CRSTI | MEN | SAL | PSO | CPSO | FAT | |
| 1. | E-FEN | * | * | * | * | * | * | * | * | * | * | * | * | * |
| P-AM | – | – | – | – | – | – | – | – | – | ± | – | – | – | |
| 2. | E-FEN | * | * | * | * | * | * | * | * | * | * | * | * | * |
| P-AM | – | – | – | – | – | – | – | – | – | – | – | – | – | |
| 3. | E-FEN | * | * | * | * | * | * | * | * | * | * | * | * | * |
| P-AM | – | – | – | – | – | – | – | – | – | ± | – | – | – | |
| 4. | E-FEN | * | * | * | * | * | * | * | * | * | * | * | * | * |
| P-AM | – | – | ± | ± | a | ± | a | a | a | ± | ± | a | a | |
| 5. | E-FEN | – | – | a | – | – | – | – | – | – | + | – | – | a |
| P-AM | – | – | – | – | – | – | – | – | – | + | – | – | – | |
| 6. | E-FEN | * | * | * | * | * | * | * | * | * | * | * | * | * |
| P-AM | – | – | – | – | – | – | a | – | – | + | – | – | + | |
| 7. | E-FEN 2 | – | – | a | – | – | – | – | – | – | ± | – | – | – |
| P-AM | – | – | a | – | – | – | – | – | – | + | – | – | – | |
| 8. | E-FEN | * | * | * | * | * | * | * | * | * | * | * | * | * |
| P-AM | – | – | – | ± | a | ± | a | a | a | ± | ± | a | – | |
| 9. | E-FEN | – | – | – | ± | a | ± | a | a | – | ± | – | – | – |
| P-AM 2,3 | – | – | – | ± | a | ± | a | a | a | – | ± | a | – | |
| 10. | E-FEN | a | a | ± | ± | a | – | – | – | – | ± | – | – | a |
| P-AM | a | a | ± | – | – | – | – | – | – | – | – | – | – | |
| 11. | E-FEN | – | – | a | ± | a | ± | a | a | – | ± | – | – | – |
| P-AM | – | – | – | ± | – | ± | a | a | a | ± | – | – | – | |
| 12. | E-FEN | * | * | * | * | * | * | * | * | * | * | * | * | * |
| P-AM | a | – | + | – | – | – | – | – | – | – | – | – | – | |
| 13. | E-FEN | – | – | – | ± | – | – | – | – | – | – | – | – | ± |
| P-AM | – | – | – | – | – | – | – | – | – | – | – | – | ± | |
| 14. | E-FEN | – | – | a | – | – | – | – | – | – | ± | ± | a | ± |
| P-AM | – | – | – | – | – | – | – | – | – | ± | ± | a | – | |
| 15. | E-FEN | – | – | – | – | – | – | – | – | – | – | – | – | a |
| P-AM | – | a | – | – | – | – | a | – | – | ± | – | – | – | |
| 16. | E-FEN | * | * | * | * | * | * | * | * | * | * | * | * | * |
| P-AM | – | – | a | – | – | – | a | – | – | + | – | – | – | |
| 17. | E-FEN | * | * | * | * | * | * | * | * | * | * | * | * | * |
| P-AM | – | – | a | ± | a | ± | a | a | a | ± | ± | a | – | |
| 18. | E-FEN | * | * | * | * | * | * | * | * | * | * | * | * | * |
| P-AM | – | – | – | – | – | – | – | – | – | – | – | – | – | |
| 19. | E-FEN | * | * | * | * | * | * | * | * | * | * | * | * | * |
| P-AM | – | – | + | – | – | – | – | – | – | – | – | – | – | |
| 20. | E-FEN | * | * | * | * | * | * | * | * | * | * | * | * | * |
| P-AM | – | – | a | + | – | a | a | – | – | + | – | – | – | |
| 21. | E-FEN2 | – | – | a | – | – | – | – | – | – | ± | – | – | – |
| P-AM | – | – | a | – | – | – | – | – | – | ± | – | – | a | |
| 22. | E-FEN | – | – | – | – | – | – | – | – | – | – | – | – | – |
| P-AM | – | – | – | – | – | – | – | – | – | – | – | – | – | |
| 23. | E-FEN | – | – | a | ±H | – | – | – | – | – | ± | – | – | a |
| P-AM | – | – | – | – | – | – | – | – | – | ± | – | – | – | |
| 24. | E-FEN | * | * | * | * | * | * | * | * | * | * | * | * | * |
| P-AM | – | – | – | – | – | – | + | – | – | + | – | – | – | |
| 25. | E-FEN | – | – | a | – | – | – | – | – | – | ± | – | – | – |
| P-AM 4 | – | – | – | – | – | – | – | – | – | ± | – | – | – | |
| 26. | E-FEN | * | * | * | * | * | * | * | * | * | * | * | * | * |
| P-AM | – | – | – | ±S | a | a | a | a | a | – | ±S | – | a | |
Usnea glaucescens Vain., U. pulvinata Motyka ex Räsänenand six infraspecific entities of U. hirta were found to represent synonyms of U. hirta (I). Clerc (1992, 1997) regards U. foveata Vain. to be conspecific with U. hirta, but we found that the type of U. foveata contains strongly modified thalli which belong to the pendent species U. barbata (L.) F.H. Wigg. s. lat. (i.e. U. scabrata s. lat.) (I). Many other Usnea taxa, mainly described by J. Motyka (e.g., Motyka 1936–1938) and V. Räsänen (e.g., Räsänen 1931), were synonymized as the result of our studies (I, III, IV). For instance, U. stuppea (Räsänen) Motyka, which was described from British Columbia, turned out to be a synonym of U. substerilis (IV). As many as ten taxa were found to represent U. glabrescens by us (III), including U. extensa Vain., which has been regarded as a distinct species by some other taxonomists (e.g., Carlin & Swahn 1977).
Table 2. The systematic grouping of the shrubby Usnea species occurring in Fennoscandia by Clerc (1987a) and Halonen et al. (III, IV). 1 = not treated by Halonen et al. (III, IV), since the species has not been found in East Fennoscandia and Pacific North America, but it is probably not a member of the Usnea fragilescens agg., 2 = not treated by Clerc (1987a), 3 = a synonym of U. glabrescens (III), 4 = represents an unidentified pendent species (III), ? = the systematic status of the species is not clearly indicated by Clerc (1987a).
| Species | ||
|---|---|---|
| Aggregates | Clerc (1987a) | Halonen et al. (III, IV) |
| Usnea diplotypus agg. | Usnea diplotypus | |
| Usnea substerilis | ||
| Usnea fragilescens agg. | Usnea cornuta | Usnea cornuta |
| Usnea flammea 1 | Usnea fragilescens | |
| Usnea fragilescens | Usnea glabrata 2 | |
| Usnea glabrescens agg. | Usnea extensa 3 | |
| Usnea glabrescens | ||
| Usnea hirta | Single species | Single species |
| Usnea lapponica agg. | Usnea fulvoreagens | |
| Usnea lapponica | ||
| Usnea mostruosa 4 | ||
| Usnea subfloridana agg. | Usnea florida | |
| Usnea subfloridana | ||
| Usnea wasmuthii ? | ||
| Usnea florida agg. | Usnea florida | |
| Usnea fulvoreagens | ||
| Usnea glabrescens | ||
| Usnea subfloridana | ||
| Usnea wasmuthii | ||
| Usnea rigida agg. | Usnea diplotypus | |
| Usnea lapponica | ||
| Usnea substerilis | ||