Dittrichia viscosa

Raab-Straube, Eckhard von & Raus, Thomas, 2025, Euro + Med-Checklist Notulae, 18, Willdenowia 55 (1), pp. 107-144 : 115

Dittrichia viscosa (L.) Greuter subsp. viscosa (≡ Inula viscosa (L.) Aiton subsp. viscosa ) – Fig. 6.

N Cm: Crimea: Yalta district, E of Foros, Cape Katyrly (Chekhov Cape), 44°23'41"N, 33°48'07.7"E, 2 m, limestone boulder-block beach, several plants, 27 May 2011, Ryff (herb. Ryff); ibid., outskirts of Opolzneve village, 44.40967°N, 33.94931°E, 338 m, roadside, 1 casual introduced plant, 24 Aug 2012, Levon (photos: https://www.inaturalist.org/observations/130764879); ibid., Sevastopol region, NW of Cape Sarych, coast of Laspi Bay, 44°23'36.2"N, 33°43'36.9"E, 5 m, among limestone boulders on clayey coastal cliff, 27 May 2016, Ryff (photo [Fig. 6B]); ibid., between boarding house “Palmida” and recreation centre “Izumrud-2”, 44°23'47"N, 34°43'29"E, 3–5 m, boulder-block beach, 5 Jul 2017, Ryff (YALT; photo [Fig. 6A]). – The genus Dittrichia Greuter is recorded here for the first time for Crimea. The native range of D. viscosa comprises the Atlantic Islands and the Mediterranean basin (Azores to Jordan; Danin 2004: 335; POWO 2024k). As an introduced alien, D. viscosa is reported from non-Mediterranean Europe ( Belgium, Germany, Great Britain, Ireland), Western Australia and scattered regions of North and South America ( Randall 2017; GBIF 2024d; POWO 2024k). Native populations closest to Crimea are known from NE Greece ( Dimopoulos & al. 2024; Strid 2024: 273, map 1089) and SW Bulgaria (Petrič, Topolnitsa) just N of the border with Greece ( Kuzmanov 2012: 252). Evidence from Romania turned out to be incorrect ( Greuter 2006 +). Therefore, there are no previous records from the European Black Sea coast (for Turkey, see Grierson 1975: 73, sub Inula viscosa (L.) Aiton). The species includes four accepted subspecific taxa (Greuter 2003, 2006; POWO 2024k). The plant, which was recorded by Aleksandr Levon in 2012 had been tentatively referred to D. viscosa subsp. angustifolia (Bég.) Greuter (det. D. Frade). However, all plants seen by us from Crimean localities have soft, opaque, oblong-lanceolate, manifestly serrulate leaves, up to 30 mm wide and therefore clearly belong to subsp. viscosa . Subsp. angustifolia differs from the type subspecies in its subrigid, shining, linear to linear-lanceolate, shortly serrulate or entire narrow leaves up to 10 mm wide ( Brullo & De Marco 2000). The two subspecies meet in Greece in a broad zone of contact, where transitional forms are not uncommon ( Dimopoulos & al. 2013: 272; 2024).

Dittrichia viscosa was first found in Crimea in May 2011 near Foros. A few plants grew among limestone boulders on the seashore together with Heliotropium sibiricum (L.) J. I. M. Melo and Rubus sp. During various searches in 2021, however, the species could not be confirmed there again. In 2016–2017, a large population of D. viscosa subsp. viscosa was discovered in a similar habitat in the SE part of the coast of Laspi Bay. The species dominated the backshore and clayey coastal cliff together with Artemisia santonicum L., Cynodon dactylon (L.) Pers., Elytrigia caespitosa subsp. nodosa (Nevski) Tzvelev , E. elongata (Host) Nevski (≡ Thinopyrum elongatum (Host) D. R. Dewey ), Jacobaea grandidentata (Ledeb.) Vasjukov , J. maritima (L.) Pelser & Meijden, Phragmites australis (Cav.) Steud. , Seseli gummiferum Sm. subsp. gummiferum , Sonchus oleraceus L. and oth- er salt-tolerant plants. It is most likely that the seeds of D. viscosa subsp. viscosa were carried to the Crimean shore by a storm, possibly entering the Black Sea with ballast water. Long-distance dispersal of the species by water and wind is known from elsewhere ( Randall 2017). Spread by migratory birds would be another conceivable means of introduction. It is unknown when exactly D. viscosa subsp. viscosa invaded the Laspi shores, but now it is completely naturalized there. Although generally Sea ( Greuter 2006 +), hence its occurrence in Albania is not surprising and was to be expected. Th. Raus