Cirsium-x-ochroleucum_7

Description:

Cirsium x ochroleucum All. (= Cirsium erisithales x Cirsium palustre) Slo.: krianec med lepkim in movirskim osatomDat.: Sept. 2. 2015Lat.: 46.36940 Long.: 13.73356Code: Bot_911/2015_DSC9180Habitat: Dirt roadside, at the border of mixed forest with Picea abies and Fagus sylvatica dominant, northwest aspect, semiruderal place; shallow, skeletal, calcareous ground; partly shady, humid and rather cool place; exposed to direct rain; average precipitations ~ 3.000 mm/year, average temperature 6-8 deg C, elevation 610 m (2.000 feet), alpine phytogeographical region.Substratum: stony soil.Place: Lower Trenta valley, roadside of a forest dirt road; south outskirts of village Trenta, left bank of River Soa, east of farmhouse Maselc, East Julian Alps, Posoje, Slovenia EC. Comment: Species of genus Cirsium are prone to hybridization. Since we have 16 species and subspecies of this genus growing in Slovenia the theoretical number of possible crosses is huge. Of cause, not all combinations are possible in real life; nevertheless, many different crosses have been described and named. The determination of them is not always easy. But the plant photographed is relatively easy recognizable hybrid between Cirsium palustre and Cirsium erisithales. Both parents are present in lower Trenta valley. Particularly Cirsium palustre is common on slopes on the left bank of river Soa, which are in shade of a mountain and moister than on the right banks because of topography and local geology. Large, deeply lobed and soft leaves situated mainly at the lower part of the stem, sparsely branched habitus with long branches, thin, spine-free stem and hanging flower heads are typical traits of Cirsium erisithales, while spiny edges of the leaves and their upper side surface, deeply decurrent leaf base, size and shape of the flower heads and purple color of the flowers origin in Cirsium palustre (C. erisithales is pale yellow).There was only a single plant growing there. This is the first time I've seen this interesting hybrid. Ref.:(1) Personal communication with Dr. Igor Dakskobler, Jovan Hadi Institute of Biology, Slovenian Academy of Art and Science, Tolmin (confirmation of determination).(2) M.A. Fischer, W. Adler, K. Oswald, Exkursionsflora fr sterreich, Liechtenstein und Sdtirol, LO Landesmuseen, Linz, Austria (2005), p 929 and p 931.(3) A. Martini et all., Mala Flora Slovenije (Flora of Slovenia - Key), Tehnina Zaloba Slovenije (2007) (in Slovenian), p 678 and p 679. (4) D. Aeschimann, K. Lauber, D.M. Moser, J.P. Theurillat, Flora Alpina, Vol. 2., Haupt (2004), p 584 and p 590.