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

252 Halonen • ANN. BOT. FENNICI 36 (1999) lectotypes). Chemistry: usnic, salazinic, barbatic and 4- O - demethylbarbatic (trace) acids. Usnea cinchonarum (Fée) Vain. var. borealis Räsänen., Ann. Acad. Sci. Fenn., Ser. A4, 34(4): 18. 1931. — Type: Estonia. Harjumaa, Keila, ad corticem Laricis , 1929 Räsä- nen (H!, lectotype, here designated). Chemistry: usnic, sala- zinic, protocetraric, barbatic and 4- O -demethylbarbatic ac- ids. — Syntypes (not found): Estonia. Tartumaa, Kastre- Peravalla, an Hainfichte, Linkola ; Võrumaa, Vaabina, Kure- nurme, an Fichte, Reinthal . Usnea comosa (Ach.) Vain. var. stuppea Räsänen, Ann. Missouri Bot. Garden 20: 9. 1933. — Usnea stuppea (Räsä- nen) Mot., Usnea 1: 262. 1936. — Type: Canada. British Columbia, Hazelton, ad corticem Pini murrayani , 1931 Ku- jala (H!, lectotype designated by Halonen et al. 1998: 57; Gyelnik, Lichenoth. no. 17; H!, LBL!, isolectotypes). Chem- istry: usnic and salazinic acids. Usnea hirta (L.) F. H. Wigg. var. romanica Räsänen, Acta Fauna Fl. Universali, Ser. 2, Bot., 2(1): 4. 1935. — Type: Romania. Buzau District, Mt. Buzau, Valea Tigva, 1933 Chirila (H!, holotype?). Chemistry: usnic and salazinic acids. — The specimen was misidentified as Usnea lappo- nica by Halonen and Puolasmaa (1995: 134). Usnea monstruosa Vain. var. balcanica Räsänen, Acta Fauna Fl. Univ. Bukarest, Ser. 2, Bot., 2(1): 4. 1935. — Type: Romania. Distr. Muscel, Cretisoara by Câmpulung, Quercus , 1935 Bordusanu (H!, holotype?). Chemistry: usnic acid. — The thalli are strongly modified and compact rep- resenting probably Usnea substerilis . Thallus erect, rarely subpendent, to ca. 8(–12) cm long, usually richly branched. Branching iso- tomic-dichotomous or anisotomic especially near the extremities. Branches normally slender, to ca. 1.3(–1.8) mm in diam., often with foveoles or depressions. Annular cracks often slightly con- stricted, rarely with everted medullary tissues. Base pale or shortly brown black to distinctly blackened. Cortex usually relatively thin, 6– 9 – 13% ( n = 12). Medulla normally lax and relatively thin, 10– 20 –28% ( n = 12). Central axis usually relatively thick, 31– 42 –54% ( n = 12). Papillae low to more often cylindric, generally numerous. Fi- brils fairly sparse to more often abundant, com- monly present also near apical parts. Soralia ( see Clerc 1987b: 101, Halonen et al. 1998: 39) tuber- culate to slightly excavate (especially old soralia near apices) and often irregular in shape, devel- oping mainly on tubercles and low pustules; soredia usually ± granulose. Isidia short, quite common on young soralia but normally abraded on mature soralia. Chemistry . Strain 1 ( n = 35): usnic + salazinic ± protocetraric (trace) acids ± unknown fatty acid A2/B3 (K+ yellow, orange or red, PD+ yellow or orange); strain 2 ( n = 8): usnic acid (K–, PD–); strain 3 ( n = 5): usnic + salazinic + barbatic ± 4- O -demethylbarbatic ± protocetraric (trace) acids (K+ yellow, orange or red, PD+ yellow or orange); strain 4 ( n = 1): usnic + salazinic + norstictic ac- ids (K+ red, PD+ orange). The specimen contain- ing norstictic acid is morphologically a typical representative of Usnea substerilis , but it may be a hybrid, since norstictic acid is not known before in U. substerilis and its close species. Remarks . Usnea substerilis is close to U. diplo- typus and U. lapponica ( see the comments under the species). Soralia of U. substerilis are only rare- ly abundantly isidiate in the East Fennoscandian material, while the species often has abundant isidia in Central Europe and British Columbia, for instance. Because of the minor morphological differences between U. lapponica and U. substeri- lis , and the intermediate morphs, a more suitable taxonomical status for U. substerilis may rather be a subspecies of U. lapponica . Ecology . The species has been collected main- ly from Picea (23%), Betula (18%) and Pinus (10%), and less frequently from Sorbus , Prunus , Salix , Populus , Alnus , Tilia , Acer , Fraxinus , Ma- lus , Larix and lignum (in total 62 specimens). Us- nea substerilis occurs relatively more often in in- habited areas than U. lapponica . Distribution . Finland: 1–3, 5–7, 9–17, 19; Rus- sia: 1, 3, 6, 10, 13, 16. World distribution: seem- ingly circumpolar from boreal to southern tem- perate regions (Halonen et al. 1998). Usnea sub- sterilis has a wide range in East Fennoscandia, but it is distinctly less common than U. lapponica in most regions. Based on preliminary studies by the first author, Vitikainen et al. (1997) reported Usnea substerilis also from Inarin Lappi. The specimens cannot be determined with certainty, however, but they represent U. lapponica s. lato. Selected specimens examined . — Finland . Varsinais- Suomi: Raisio, 1931 Auer (TUR), strain 1. Etelä-Häme: Hat- tula, Lepaa, Vahopää, 1935 Räsänen (H), strain 1. Pohjois- Häme: Äänekoski, Pukkimäki, 1947 Klingstedt (H), strain 2. Keski-Pohjanmaa: Sievi, Korhonen, 1967 Kosonen (OU- LU), strain 1. Kainuu: Paltamo, Melalahti, Viilonkallio, 1959 Huuskonen (H), strain 1. Oulun Pohjanmaa: Oulu, San- kivaara, 1988 Halonen (OULU), strain 3. Sompion Lappi: Sodankylä, Korvanen, Vuollosvaara, 1958 Ulvinen (OU- LU), strain 3. Russia . Leningrad Region. Karelia australis: Yashino (Vahviala), Hämeenvaara, 1938 Fagerström (H),