Erigeron politus Fr. in Bot. Not. 1843: 120 (1843)

Sennikov, Alexander N. & Kozhin, Mikhail N., 2023, Taxonomic revision of the Erigeron acris group (Asteraceae) in Murmansk Region, Russia, reveals a complex pattern of native and alien taxa, PhytoKeys 235, pp. 83-128 : 83

1. Erigeron politus Fr. in Bot. Not. 1843: 120 (1843)

Fig. 3

Erigeron acris politus - Erigeron acris var. politus (Fr.) Mela, Lyhyk. Kasvioppi Kasvio, ed. 1: 66 (1877) - Erigeron acris subvar. politus (Fr.) Mela, Lyhyk. Kasvioppi Kasvio, ed. 2: 79 (1884) - Erigeron droebachiensis var. politus (Fr.) Mela, Suomen Kasvio, ed. 3: 174 (1895) - Erigeron acris subsp. politus (Fr.) H.Lindb., Enum. Pl. Fennoscand. Orient.: 56 (1901).

Erigeron elongatus = Erigeron elongatus Ledeb., Icon. Pl. Fl. Ross. 1: 9 (1829), nom. illeg., non Moench (1802) - Erigeron acris var. elongatus Herder in Bull. Soc. Imp. Naturalistes Moscou 38(2): 391 (1865) - Erigeron acris subsp. elongatus (Herder) Kindb., Svensk Fl.: 296 (1877) - Erigeron acris f. elongatus (Herder) Mela, Lyhyk. Kasvioppi Kasvio, ed. 1: 66 (1877) - Erigeron droebachiensis subsp. elongatus (Herder) Mela, Suomen Kasvio, ed. 3: 174 (1895). Type. Russia. “Altai”, 1826, Herb. Ledebour 1308 (lectotype LE 1043841, designated here; isolectotype LE 1043843).

Type.

Norway. "Norvegia austr. fr.," M. Blytt [ E. Fries, Herbarium Normale VIII: Suppl. no. 1b] (lectotype H 1642416, designated here). Fig. 2 . Superseded neotype : Sweden. "Jmt. Duved," 23.07.1931, Th. Brandt (LD 1367491, designated by Olander and Tyler (2017: 46)) .

Description.

Stems 25-40 cm tall, branched in the upper third, intensely purple-coloured to nearly green, completely glabrous or covered by scattered hairs 0.5-0.8 mm long. Cauline leaves 3-8 under the synflorescence, spaced, gradually decreasing towards the stem top, nearly glabrous on both sides, hairy mostly along margins. Synflorescence with long branches carrying solitary to 2-3 capitula, nearly corymbose at the top, glabrous or with solitary hairs. Phyllaries 6-7.5 mm long, purple-coloured completely or near the apex, covered by sparse hairs in the lower part or near the base, or nearly glabrous. Ray flowers dark-lilac to pale-pinkish. Pappus greyish-white.

Flowers in July, fruits in August.

Distribution in Murmansk Region.

Khibiny Mtrs., Lovozero Mts., Turii Mys, Kutsa River, Ponoi River, Orlov Cape, Kandalaksha Gulf, Rybachii Peninsula, Ambarnaya (Pikku Maattivuono) Bay, Drozdovka Village, Chapoma Village (Fig. 4A ).

Global distribution.

Subarctic and Northern Boreal zones of Fennoscandia, Eastern Europe and Asia, mountains of southern Siberia (Altai).

Nomenclatural note.

The circumstances of the valid publication of Erigeron politus are rather peculiar. Fries (1843a) mentioned two variants of his E. elongatus , which included subglabrous, presumably perennial plants of Norwegian mountains and Lapland, of which the first one corresponded to E. droebachiensis and the second one was deemed to be the same as E. glabratus in Hooker (1834) and E. villarsii Bellardi in Hartman (1838). A plant of the first variant was distributed by him in his exsiccatae, "Herbarium Normale" ( Fries 1842). Shortly thereafter, Fries (1843b) changed his mind and decided that the first variant ( E. droebachiensis , which he considered the same as E. elongatus ), was annual and the second variant was perennial, and described the latter as a new species, E. politus . To complement the plant distributed in "Herbarium Normale" ( Fries 1842), he issued a supplement to this fascicle, which contained the only number ( Fries 1843c), most probably distributed along with the protologue in August 1843. This supplement seems to be very rare in collections. Olander and Tyler (2017) were unable to trace a specimen of that gathering at S and UPS, but a good specimen is available at H. This specimen is designated here as lectotype, thus superseding the neotype designated by Olander and Tyler (2017). The lectotype has dark glabrous phyllaries 6-7 mm long, 7 capitula on long branches and much exserted ray flowers (extending the pappus up to 3 mm), and thus fully corresponds to E. politus as accepted in Olander and Tyler (2017).

Taxonomic note.

The main distribution area of E. politus in Murmansk Region consists of a few separate areas. Plants occurring in these areas are characterised by small but noticeable differences. Plants from the Kutsa River are exceedingly glabrous, with regularly glabrous stems and almost totally glabrous leaves, which are hairy largely along the margins; their involucres are hairy mostly at the base but forms with sparingly hairy involucre surfaces are also known. In Petsamo, plants have their involucres more regularly hairy in the basal half, and their stems are regularly but sparsely hairy. Similar plants are found in the Khibiny and Lovozero Mts., and along the Barents Sea coast. However, the plant hairiness is not completely constant, and deviating individuals can be found in all populations.

Figures

Figure 2. Lectotype of Erigeron politus Fr. (H 1642416). Courtesy of the Finnish Museum of Natural History, University of Helsinki.

Figure 3. Lectotype of Erigeron elongatus Ledeb. (LE 1043841). Courtesy of the Komarov Botanical Institute, Russian Academy of Sciences.

Figure 4. Distribution of the Erigeron acris group in Murmansk Region, Russia A E. politus F. B E. x pilosiusculus Sennikov C E. rigidus Fr. D E. x intercalaris Sennikov. Origin and residence status: green - native; yellow - pre-industrial alien; red - industrial alien. Maps were created using ArcGIS software by Esri. ArcGIS is the intellectual property of Esri and is used herein under license. Copyright Esri. All rights reserved.