Petrova O. The lichen genus Usnea in eastern Gennoscandia. III Shrubby species. Ann. Bot. Fennici. 1999, 36, p. 235-256.

250 Halonen • ANN. BOT. FENNICI 36 (1999) ra, 1938 Fagerström (H), strain 1. Isthmus karelicus: Kone- vitsa, 1938 Räsänen (H), strain 2. Republic of Karelia. Kare- lia ladogensis: Hiitola, Mustolan hovi, 1933 Räsänen (H), strain 1. Karelia olonetsensis: Vedlozero (Vieljärvi), Pihti- lahti, 1942 Railonsala (TUR), strain 1. Murmansk Region. Lapponia Imandrae: Zasheyek (Sascheika), 1861 Fellman (H), strain 1. Lapponia Varsugae: Ponoi River, Krasnoshche- le, 1990 Dudoreva (KPABG), strain 3. 7. Usnea subfloridana Stirt. Scott. Naturalist (Perth) 6: 294. 1882. — Type: Scotland. Perthshire, Killin, 1881 Stirton (BM!, holotype). Chemis- try: usnic and thamnolic acids (TLC by D. L. Hawksworth) — see also Laundon (1965). Lichen comosus Ach., Kongl. Svenska Vetenskapsakad. Handl. 1795: 209. 1795. — Usnea comosa (Ach.) Vain., Meddeland. Soc. Fauna Fl. Fenn. 48: 173. 1925 (‘1924’), nom. illeg. ( non Usnea comosa Pers.). — Type: Sweden (H-ACH 1857c!, lectotype designated by Clerc 1987a: 494). Chemistry: usnic, thamnolic and hypothamnolic acids. Usnea comosa (Ach.) Vain. subsp. similis Motyka, Wy- daw. Muz. S l a sk. Katowice, Dzia l 3, 2: 18. 1930. — Usnea similis (Motyka) Räsänen, Ann. Acad. Sci. Fenn., Ser. A4, 34(4): 19. 1931. — Usnea subfloridana subsp. similis (Mo- tyka) Bystrek, Stud. Flechtengatt. Usnea Europa 48, 54. 1994, nom. inval. (basionym not cited). — Type: Poland. Silesia, P l askowy z ; Grabowa; Malinka; Barania Góra, 1928 Motyka (LBL, syntypes, n.v. , a lectotype should be desig- nated among them). — The “type” in Motyka (1936: 270): “Polonia, Montes Lysogory, in m-te Lysica” cannot be re- garded as the type, since it is not cited in the protologue. — Usnea similis clearly represents the thamnolic acid strain (K+) of Usnea subfloridana . Usnea australis Vain. var. wainioi Räsänen, Ann. Acad. Sci. Fenn., Ser. A4, 34(4): 19. 1931. — Usnea similis (Mo- tyka) Räsänen var. wainioi (Räsänen) Räsänen, in Cretzoiu, Rev. Bryol. Lichénol. 10: 28. 1937. — Type: Estonia. Võrumaa, Kurenurme-Vaabina, an Picea excelsa , Reinthal (holotype, not found). — Type: Russia. Leningrad Region, Isthmus karelicus, St. Petersburg City, Roshchino SW (for- merly Uusikirkko, Raivola), Larix sibirica , 1924 Kujala (H!, neotype, here designated). Chemistry: usnic and thamnolic acids. — The specimen is labelled as Usnea similis var. wainioi , but it was commented by Motyka (1936: 304), and evidently thereafter the epithet ‘ australis ’ on the label was changed to ‘ similis ’ by Räsänen. The specimen apparently represents Räsänen’s (1931) statement “im südlichen Finn- land...”. Usnea comosa var. stuppeiformis Räsänen, Lich. Fenn. Exs. no. 16 (Schedae: 6). 1935. — Type: Russia. Republic of Karelia, Karelia ladogensis, Kurkijoki, Heposaari, ad corticem Pruni padi , 1932 Räsänen (H!, lectotype, here designated; H!, KUO, S!, TUR!, isolectotypes). Chemis- try: usnic and thamnolic acids. Usnea comosa f. albida Räsänen, Ann. Bot. Soc. Zool. Bot. Fenn. Vanamo 12(1): 48. 1939. — Usnea albida (Räsä- nen) Räsänen, Kuopion Luonnon Ystäväin Yhdistyksen Julkaisuja, Ser. A, 5: 63. 1951. — Type: Russia. Republic of Karelia, Karelia ladogensis, Kurkijoki, Maasilta, ad corti- cem Populi tremulae , 1933 Räsänen (H!, holotype). Chem- istry: usnic and squamatic acids. Usnea comosa f. perisidiosa Räsänen, Ann. Bot. Soc. Zool. Bot. Fenn. Vanamo 12(1): 48. 1939. — Type: Esto- nia. Virumaa, Simuna, Rohu, Pinus silvestris imWalde von Nõmme, 1869 Bruttan ? (H!, holotype). Chemistry: usnic and thamnolic acids. Usnea similis var. peraspera Räsänen, Ann. Bot. Soc. Zool. Bot. Fenn. Vanamo 20(3): 7. 1944. —Type: Estonia. Virumaa, Simuna, Rohu, ad ramos Pini silvestris , 1869 Bruttan (holotype, not found). — The taxon may be homo- typic with Usnea comosa f. perisidiosa , i.e. the same speci- men has been described twice under different names. — Type: Estonia. Viljandimaa, Puiatu, Nutru, ad cort. pini, 1934 Rebane (H!, neotype, here designated). Chemistry: usnic and thamnolic acids. — The label of the specimen is inscribed “original” by Räsänen. Thallus erect, later occasionally becoming sub- pendent or rarely pendent, to ca. 12(–20) cm long, usually quite richly branched. Branching mainly isotomic-dichotomous. Branches normally slen- der, to ca. 1.3(–2) mm in diam. Annular cracks sparse to relatively abundant, occasionally with distinct medullary rings. Base distinctly black- ened, rarely with longitudinal cracks. Cortex rela- tively thick, 10– 12 –15% ( n = 18). Medulla dense, usually relatively thin, 7– 14 –21% ( n = 18). Cen- tral axis relatively thick to thick, 32– 47 –66% ( n = 18). Papillae short to more rarely cylindric, usu- ally numerous. Fibrils relatively sparse to copi- ous near basal portions, absent to sparse near api- cal parts. Soralia (Fig. 7) tuberculate to slightly excavate (especially near apices), minute to en- larged; soredia farinose. Isidia usually short and numerous but absent on excavate soralia. Chemistry . Strain 1 ( n = 460): usnic + squama- tic acids (K–, PD–, UV+ whitish blue); strain 2 ( n = 396): usnic + thamnolic acids (K+ yellow, PD+ yellow-orange, UV–); strain 3 ( n = 10): usnic + squamatic + thamnolic acids (K+ yellow, PD+ yellow-orange, UV+whitish blue). The thamnolic acid strain is the main chemotype only in three southern-coastal provinces, namely Åland (18 of 23 studied specimens), Karjalan kannas (22 of 36 studied specimens) and Laatokan Karjala (71 of 106 studied specimens). The strains are approxi- mately equal in frequency in Varsinais-Suomi and Uusimaa on the southern coast and along the coast of the Gulf of Bothnia. In the other regions the