Cirsium greimleri

Stems Cirsium greimleri is a perennial species. and occasional sterile basal rosettes. Leaves Leaves grow all along the stem. Their shallow feathered (pinnate) lobes are doubly toothed (serrate) to pinnatipartite, with weak yellowish to brownish-purple spinules up to 2 millimetres situated at the margins, All leaves are soft and herbaceous. Micromorphology Stomatal guard cells are about 16.5 micrometres long and 9.2 μm wide. with each head containing between 1 and 8 individual flowers. These flower heads can be solitary or arranged in clusters (corymbosely) at the top of the stem, sometimes appearing on 1 to 5 side branches (lateral pedicels). The pollen is coarsely spined. Petals are is 17.3 to 21.0 mm long in hermaphrodites, and 15.1 to 18 mm in females. Fruit Strongly wind-dispersed (anemochorous), its fruits contain oblong, compressed, asymmetric greyish ochre achenes, 16 to 19 mm in hermaphrodites, 14.5 to 18.0 mm in females. They are attached to either 4 or 5 mm pappi. The average dry weight of 1000 seeds is 0.4 g. Chromosomes C. greimleri is a diploid species with sporophytic chromosome number 2n=2x=34, without variation. Its somatic nuclear DNA size is about 1929 Mega base pairs. Similar species C. waldsteinii is genetically close and almost identical in appearance. In the field, the main distinguishing traits are lobe depth and flower colour. Although their basal leaves are roughly equal in width, the cauline leaves of C. waldsteinii are significantly wider, though the significantly deeper lobes of the latter may create the appearance of narrowness. The apparent broadness of C. greimleri leaves is distinctive within the genus. The corollae of C. waldsteinii are lighter in colour at any given stage, with little overlap in hue after opening (though both can be greyish violet at full bloom). Any comparison must be made between flowers of roughly equal stage. The green colour of its stems below the capitula are slightly visible, unlike the completely covered C. greimleri. C. hypoleucum . Its nodding flowers are sometimes ruby red like those of C. greimleri, which is rare for the genus. The leaves of C. hypoleucum, sometimes resembling C. waldsteinii more than C. greimleri, are white-tomentose beneath, in contrast to the greyish-arachnoid leaves of C. greimleri. The involucral bracts of C. greimleri gradually become longer inward. The involucres of C. hypoleucum differ markedly in colour from those of C. greimleri, and the involucres themselves are narrower. The idumentum of subcapitular stem is sparser. C. carniolicum . Very similar to C. greimleri in vegetative stage, but with yellow to white flowers with tougher phyllaries and spiny sepals, visible green colour through the pilosity of the subcapitular stem, and more distinctive spines on upper cauline leaves with subglabrous undersides. C. alpis-lunae is a C. carniolum like species with spiny phyllaries and longer, stiffer leaf spines but no overlap with C. greimleri. A number of species of the Caucasus can be difficult to distinguish from the species: C. oblongifolium (longer, oblong leaves, glabrous leaf undersides), C. pseudopersonata (lighter flower colour, thinner subcapitular idumentum, glabrous leaf undersides), C. sychnosanthum (glabrous leaf undersides), C. uliginosum . A number of species have a similar flower colour but little resemblance otherwise: C. rivulare var. 'Atropurpureum' , C. borealinipponense , C. hachimantaiense , C. hidakamontanum , C. shimae , C. chokaiense , C. douglasii , C. occidentale . Such a flower colour can result from hybrids between yellow-flowered C. eristhales and purple-flowered species (such as C. alsophilum, C. palustre, C. pannonicum, C. rivulare). Hybridisation between the ancestor of C. greimleri and a yellow-flowered species like C. eristhales or C. carniolicum may be the reason the former has a different flower colour from C. waldsteinii. The unusually wide leaves of C. greimleri are even rarer in the genus. Apart from C. carniolicum, their width is approached only by Madeira endemic C. latifolium , with which there is little risk of confusion otherwise. ==Taxonomy==

Etymology The species is named after botanist Josef Greimler, whose chromosome count spurred the study that separated it from C. waldsteinii. C. waldsteinii was grouped with C. eristhales over C. greimleri in a 2023 paper, but the phylogeny was based on genome size, GC-content, achene length, and guard cell length, rather than genetics. Taxonomic history specimen collected by Michael Hölzl in 1837 Its holotype BRNU 658042 was collected by Petr Bureš at 1739 m from in the Rottenmann and Wölz Tauern on 15 September 2015. C. greimleri had been considered part of C. waldsteinii until 2018. In 2018, following the discovery that Alpine-Dinaric populations of "C. waldsteinii" were invariably diploid, whereas Carpathian populations were invariably tetraploid, the Alpine-Dinaric and Carpathian populations were split into two species. This decision was corroborated by physical and genetic evidence of separation. Unpublished, the first record of what is now considered C. greimleri may have been a Tyrolian record in an 1807 catalogue by Johann Christoph Schleicher, but this is dubious. It was first published within its present genus as Cirsium pauciflorum by Anton Eleutherius Sauter following its discovery in Rottenmanner Tauern. In 1905, C. pauciflorum was recognised to be a younger homonym of C. pauciflorum , which is now designated Carduus defloratus. Because of this, they assigned it a new name, C. waldsteinii. ==Distribution and habitat==

Distribution It is found in the Eastern and Dinaric Alps. A partial but detailed map is designated Obr. 32b in Vavrinec 2020, which also provides distribution maps for its hybrids. The precise ranges it has been found on include the Ennstal Alps, Rottenmann and Wölz Tauern, Seckau Tauern, Seetal Alps, Saualpe, Koralpe, Karawanks, Kamnik–Savinja Alps, Pohorje, Julian Alps, Snežnik, Srnetica, Klekovača, Cincar, Vranica, Bjelašnica, Visočica, Treskavica, Zelengora, Jahorina, Komovi, Golija, and Kopaonik. and somewhat similar to those of Achillea clusiana, Moehringia ciliata, and Vicia oroboides. Or to the acidophile species Hieracium transylvanicum. found from 800 to 2000 m. It grows on moist downwind slopes and on roadsides in valleys with running water in the more montane part of its range, but also in more open scree forests in the more subalpine part of its range. C. greimleri has an extremely low shade tolerance, 5 for temperature, requiring a continental climate with moderate soil moisture, It has no halotolerance. The overlapping, or coterminous Cirsium species with the greatest ecological similarity is C. arvense, followed by C. heterophyllum and C. spinosissimum. The species is calcifuge, requiring moderately acidic soil pH, but does sometimes grow on calcareous substrates, so long as it is very richly fertile soil. ==Ecology==

Reproduction Flowering is from late June to late July, to early August at sites of higher shade or altitude. some hermaphrodite and others female (rudimental synantheria, without developed pollen), in addition to sterile individuals that do not progress beyond rosette stage. Hermaphrodite flowers can be distinguished visually by the protrusion of their synantherium from the corolla, by colour of their synantherium, by the pollen pushed out by an elongating style at full anthesis (female synantheria lack pollen). Hermaphrodite synantheria are longer, at 6.7 to 9.3 mm, compared to female synantheria, at 4.3 to 5.7 mm. The same applies to styles, 20 to 25 mm in hermaphrodites, and 18.0 to 22.4 mm in females. Although both hermaphrodite and female stigmas can be straight, only female stigmas can be twisted, and usually are. Suggested explanations for the aberrance of C. greimleri and C. waldsteinii include larger achene count, higher germanation rates, and lower infestation with achene predators like the Tephritidae and Curculionidae. It is sometimes an element of the Scabioso hladnikianae-Grafietum golakae association. It is a rare element of the Calamagrostion arundinaceae association, and the Polysticho-lonchitis-fagetum rhododendrotosum hirsuti subassociation. Cirsio cani-Filipenduletum ulmariae, Caricion davallianae, and Veronico-Calitrichetum. ==Conservation==

It readily forms hybrids, with the highest degree of promiscuity in its genus among the Cirsium species of the Pannonian Basin, leaving it vulnerable to genetic erosion through local imbalances in pollen production, leading to unidirectional geneflow, for which reason it is regarded as an endangered species. Most populations consist of only a few to several hundreds of individuals, and only the Koralpe and Seetaler Alpen have known populations with over a thousand. Within its genus, an erosion risk is not unique to C. greimleri, applying also to C. alsophilum, C. bertolonii, and C. carniolicum. A collection of seeds for the Millennium Seed Bank was made in 2014. ==See also==