Taraxacum tenuilobum (Dahlst.) Dahlst., Acta Fl. Sueciae 1: 47, 50, 85. 1921.

Wolanin, Mateusz, Klichowska, Ewelina, Jedrzejczyk, Iwona, Rewers, Monika & Nobis, Marcin, 2023, Taxonomy and distribution of Taraxacum sect. Erythrosperma (Asteraceae) in Poland, PhytoKeys 224, pp. 1-88 : 1

13. Taraxacum tenuilobum (Dahlst.) Dahlst., Acta Fl. Sueciae 1: 47, 50, 85. 1921.

Taraxacum erythrospermum subsp. tenuilobum Dahlst., Bot. Not., 1905: 167. 1905.Basionym.

Type.

Sweden, Dalsland, Mo, Ojersbyn, on rock, 24 May 1901, P.A. Larsson (lectotype in S, designated by G. Haglund in Doll 1973: 86; isolectotype in S) .

Description.

Plants small to middle-sized, (5-)10-15 cm tall. Leaves grey-green, almost glabrous or with few barely visible hairs, approximately (5-)7-12(-15) cm long and (1.5-)2.5-3.5(-4) cm wide, usually 4-5 times longer than wide, blades narrowly oblanceolate, usually broadest in upper 1/3, with 3-7 pairs of lateral lobes; lateral lobes opposite to remote; lateral lobes of the inner leaves strongly dissected, somewhat recurved and twisted, quite often slightly widening at the apex, often with parallel small and acute lobes at the distal margin base; lateral lobes of the outer leaves narrowly triangular, slightly recurved or patent, quite often incised or toothed at the distal margin base; interlobes long, often lobulate; terminal lobe of the inner leaves elongate with a protracted apex; terminal lobe of the outer leaves tripartite-subsagitate, quite often with the apical lobule slightly widening at the apex; petioles unwinged, purple. Scapes as long as or shorter than leaves, hairy, especially just under the capitulum. Capitulum convex, 2.5-3.5 cm in diameter, yellow, outer strips grey-violet; inner bracts greyish-green, often with small lumps; outer bracts usually 10-15, narrowly lanceolate, usually 6-8 mm long, 1.5-2 mm broad, bright greyish-green, suffused with violet, faintly bordered (up to 0.05 broad), arcuate, without corniculation or sometimes with small cornicules; stigmas dark greyish-green, pollen present. Achenes red-brown, in the upper part with slender spinules, 3.5-4.0 mm long (incl. the 0.8-1.1 mm long, cylindrical cone), rostrum 6-7 mm long, pappus white.

Flowering period.

April-May.

Habitat.

In the northern part of Poland, this species grows most often in dry and sandy habitats, such as sandy grasslands, roadsides of forest roads, edges of pine fo-rests, paths, cliffs, dunes, and lawns. In southern Poland, we noticed this species most often in rock grasslands (in eroding and trampled areas). Plant communities with the participation of T. tenuilobum were predominated by species typical to the Festuco-Brometea (especially in S Poland) and Sedo-Scleranthetea classes. In Świętokrzyskie Mts (Miedzianka place) we noted this species in rocky grassland growing together with Allium montanum , Arenaria serpyllifolia , Artemisia campestris , Camelina microcarpa subsp. sylvestris , Campanula sibirica , Centaurea stoebe , Cerastium semidecandrum , Dianthus carthusianorum , Euphorbia cyparissias , Galium mollugo , Holosteum umbellatum , Medicago falcata , Plantago media , Poa compressa , P. pratensis , Potentilla argentea , Ranunculus bulbosus , Salvia pratensis , Sanguisorba minor , Sedum acre , Silene nutans , Stachys recta , Thymus pulegioides , Verbascum nigrum , Vincetoxicum hirundinaria , Viola arvensis . On the coast of the Baltic Sea ( Łeba place) we observed these species on the sandy edge of the pine forest, accompanied by Carex arenaria , Cerastium semidecandrum , Erophila verna , Potentilla argentea , Vicia lathyroides .

Somatic chromosome number.

24 ( Wolanin and Musiał 2017), 25 ( Małecka 1969).

General distribution.

Mainly NE part of Europe. Species reported from Switzerland, Germany, the Netherlands, Denmark, Poland, Sweden, Norway, Crimea, Moldova, Ukraine, Latvia, Estonia and European Russia ( Van Soest 1969; Tutin et al. 1976; Tacik 1980; Fedorov 1989; Lundevall and Øllgaard 1999; Mosyakin and Fedoronchuk 1999; Uhlemann 2003; Wendt and Øllgaard 2015).

Distribution in Poland.

Localities grouped in 4 separate areas in northern and southern Poland; quite frequent only in Podlachia and on the coast of the Baltic Sea (Fig. 36A ).

Specimens examined.

BA59 - Ustka, path, 54°35'25"N, 16°53'07"E, 1 May 2017, M. Wolanin (003309 UR); BA76 - Darłówko, sands, 54°26'45"N, 16°23'41"E, 1 May 2017, M. Wolanin (003323 UR); BA84 - Łazy, path in pine forest, 54°18'16"N, 16°11'16"E, 1 May 2017, M. Wolanin (003346 UR); CA38 - 1,5 km E of Rozewie, cliff, 30 May 1961, Monk / Mark (152/2 UGDA); CA43 - Łeba, path in pine forest, 54°46'05"N, 17°34'06"E, 1 May 2017, M. Wolanin (003336 UR); DA60 - south of Babie Doly , cliff, 12 May 1970, W. Chojnacki (153/01 UGDA); DA70 - Sopot, lawn near promenade, 54°27'26"N, 18°33'43"E, 8 May 2016, M. Wolanin (003296 UR); DA80 - Wisłoujście ( Gdańsk), lawn, 54°23'37"N, 18°40'36"E, 7 May 2016, M. Wolanin (003552 UR); DA82 - Świbno, sandy roadside in forest, 54°20'18"N, 18°56'12"E, 10 May 2016, M. Wolanin (003283 UR), DB60 - near Jaszczerek, sandy roadside, 53°37'02"N, 18°35'16"E, 1 May 2019, M. Wolanin (003575 UR), DF06 - Kroczyce, grassland and paths on calceolus rock (SW slope), 50°34'18"N, 19°31'47"E, 1 May 2013, M. Wolanin (003359 UR); Podlesice, rock close to cave, grassland on rock, 50°34'30"N, 19°31'32"E, 1 May 2021, M. Wolanin (003593 UR); Mirów, grassland on rock overgrown by shrubs, 50°36'53"N, 19°28'51"E, 1 May 2021, M. Wolanin (003595 UR); EE72 - Miedzianka hill, grassland on rock, 50°50'49"N, 20°21'32"E, 11 April 2016, M. Wolanin (003514 UR); EE83 - Sosnówka hill, grassland on rock, 50°48'24"N, 20°26'15"E, 11 April 2016, M. Wolanin (003500 UR); FB59 - between Wrotki and Mogielnica, dry pasture, 53°39'45"N, 22°58'11"E, 24 April 2016, M. Wolanin (003270 UR); FB76 - Sośnia, dunes on pasture, 8 May 2003, Z. Głowacki (0388261 KRA); FC11 - Czartoria, hillock close to river, 8 May 2016, T. Grużewska (MPD); FC13 - Piątnica ( Fort Lomza ), pastured sandy grassland, 53°11'48"N, 22°07'00"E, 24 April 2016, M. Wolanin (003539 UR); FC27 - Truskolasy-Lachy, stoned field road close to old excavation, 53°02'23"N, 22°42'11"E, 2 May 2018, M. Wolanin (003481); FC34 - Zbrzeźnica, psammophilous grassland, 53°01'24"N, 22°10'11"E, 26 April 2016, M. Wolanin (003546 UR); FC73 - Borowe nad Bugiem, Bug river sandy terrace, 52°40'22"N, 22°00'41"E, 26 April 2016, M. Wolanin (003545 UR); FD09 - Bużka, sandy roadside, 52°21'26"N, 22°53'55"E, 25 April 2016, M. Wolanin (003484 UR); GD10 - Serpelice, lawn, 52°16'49"N, 23°03'01"E, 25 April 2016, M. Wolanin (003257 UR); GF00 - Tereszpol near Biłgoraj, lawn, 50°33'13"N, 22°55'54"E, 25 April 2016, M. Wolanin (003468 UR); GF24 - Bełżec, grassland on closed railway track, 50°22'45"N, 23°26'51"E, 18 April 2019, M. Wolanin (003587 UR) .

Notes.

Plant with distinct, strongly incised and narrow side lobes, and tongue-shaped terminal lobe apex. Outer phyllaries are narrowly lanceolate, arcuate, faintly bordered. Juvenile plants can be confused with T. scanicum , which has significantly less dissected side lobes, and the outer bracts of which are wider (with distinct hyaline margin, 0.1-0.2 mm broad), recurved or patent (Figs 37 , 38 ).

Figures

Figure 36. Distribution maps of Taraxacum sect. Erythrosperma in Poland A T. tenuilobum B T. tortilobum; black square - localities recorded during field studies, black circle - other localities known from herbarium data.

Figure 37. Variation in leaf shape in T. tenuilobum; locality - Kroczyce (M. Wolanin 2016 UR). Scale bar: 5 cm.

Figure 38. Taraxacum tenuilobum; locality - Leba, 2017, photo by M. Wolanin.