Cirsium greimleri, , is a perennial species of flowering plant in the family Asteraceae. It was described as a separate species from Cirsium waldsteinii in 2018, from which it can be distinguished visually by its shallower lobes and deeper flower colour. Additionally, its leaves are unusually broad for the genus. It is one of a minority of species discovered through karyological analysis. It is a tall herbaceous plant with nodding purple flowers growing in high montane to subalpine habitats on exposed acidic slopes. It is native to Eastern Europe, but with an unusual geographic distribution. It is found only in the Eastern Alps and Dinaric Alps. It hybridises readily, to the extent that there is concern about genetic erosion for most populations.
Description Stems
Cirsium greimleri is a perennial species. Plants grow from oblique, cylindrical rhizomes to heights between 110 and 180 centimetres, with the exception of a rare form that only grows to 30 cm, and occasional sterile basal rosettes. Growth is erect but nodding below the capitula. Stems are shallowly ribbed. They are simple or have few branches. Their colour is green or reddish green but finely haired (pilose), or almost smooth (subglabrous) at the base, whitish green and sparsely webbed (arachnoid) in the middle, and white and densely arachnoid below the capitula.
Leaves
Leaves grow all along the stem. Ground level (basal) leaves are 11.5 to 23.3 cm wide and 1.2 to 2.1 cm longer than wide in mature specimens. Their morphology ranges from egg-shaped (ovate) to circular (orbicular) to triangular (deltate), especially in younger leaves. Stalk (peduncular) leaves are lobed (amplexicaul), often eared (auriculate). 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, subglabrous, to scattered hairy (pubescent), above and densely webbed-woolly (arachnoid-lanate) below. All leaves are soft and herbaceous.Reichenbach 1853. "Cirsium pauciflorum Sprengel: einfach, flockigspinnwebig, Stängel wenig-blüthig, oben nackt, unterste Blätter breit länglichdreieckig, grob buchtig gezähnt, am Rande stachlich, ober sitzend, am Grunde beiderseits geöhrt, schmäler, unterseits spinnwebig ... Blätter oberseits mit kleinen Haaren. Mächst auf grasigen Wiesen, in Wäldern. Sommer.♃" (in German) [Cirsium pauciflorum Sprengel: simple, flaky, spider-webbed, stems with few flowers, naked above, lowest leaves broadly elongated-triangular, coarsely sinuously toothed, spiny on the edge, sessile above, auriculate on both sides at the base, narrower, spider-webbed below ... leaves with small hairs on the upper side. Grows on grassy meadows, in forests. Summer. Perennial]
Micromorphology
Stomatal guard cells are about 16.5 micrometres long and 9.2 μm wide.
Flowers
The flowers of C. greimleri are grouped in flower heads (capitula), 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 protective casing around the flowers (the involucre) measures 12.9 to 21.0 mm in length during flowering. Phyllaries are arranged in 6 to 7 rows. bracts flare out from the bud, with distinct vittae. The outer bracts having a visible spine, while the inner ones do not. Involucres are purplish brown to purplish black. The flower heads abound with nectar.Fritsch 1905. "Im Tubus der Blumenkrone ist viel Honig enthalten." (in German) [The tube of the corolla contains a lot of honey.] The pollen is coarsely spined.Fritsch 1905. "Der Griffel ist während des weiblichen Stadiums der Anthese 22 mm lang, wovon nur 3 mm auf die dicht aneinandergepreßten Griffeläste entfallen. Die langen Fegehaare bilden einen auffallenden Kranz. Der Pollen ist grobstachelig." (in German) [During the female stage of anthesis, the style is 22 mm long, of which only 3 mm are the tightly pressed style branches. The long hairs form a conspicuous wreath. 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. At full flowering (anthesis), corollae average deep violet, but can be greyish violet or even ruby. During fading, corollae average dark purple, but can be lighter, dark magenta, or even dark ruby or dark violet. They ultimately fade to whitish, as does the brownish-purple (in hermaphrodites) or ochre synantherium. The style is always whitish except for the ruby shortly bi-lobed stigma, which fades to deep crimson or brownish-purple.Fritsch 1906. "Die großen Köpfchen des Cirsium pauciflorum Spr. zeichnen sich durch sehr dunkle, trübpurpurne Färbung aus. Zu dieser dunklen Gesamtfärbung tragen hauptsächlich die fast schwarzpurpurnen Griffeläste bei, welche viel dunkler sind als die Blumenkrone. Am Grunde (nämlich in dem nicht dem Lichte ausgesetzten Teule) sind alle Blütenteile, namentlich die Röhre der Blumenkrone und der Griffel, weißlich, gegen die Spitze zu wird die Färbung immer lebhafter purpurn. Die Blumenkrone ist 16–17 mm lang; hievon entfallen 5–6 mm auf den stielförmigen Teil der Röhre. Die Zipfel sind stets von ungleicher Länge, der kürzeste ist 3 mm, der längste 5 mm lang." (in German) [The large heads of Cirsium pauciflorum Spr. are characterized by a very dark, dull purple color. The almost black-purple style branches, which are much darker than the corolla, contribute to this dark overall color. At the base (namely in the part not exposed to light), all parts of the flower, especially the corolla tube and the style, are whitish; towards the tip the color becomes increasingly more vibrant purple. The corolla is 16–17 mm long; 5–6 mm of this is the stalk-shaped part of the tube. The tips are always of unequal length; the shortest is 3 mm, the longest 5 mm.]
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 pappus is whitish and feathery or strawlike.Reichenbach 1853. "Köpfe wenige, 2–4, Hüllschuppen lanzettlich, am Rand und auch gegen Rücken bis auf Mittellinie fitzig, undeutlich gekielt, an der Spitze umgeschlagen. ... Blüthchen dunkelpurpurn, Gaum bis über Mitte gespalten, Spitzen der Abschnitte verdickt. Pappusfedern an der Spitze spatelig erweitert. Pollen gut entwickelt. Achenien länglich zusammengedrückt, am Grunde schmäler, dunkelbraun." (in German) [Heads few, 2–4, involucral scales lanceolate, striate at the margin and also towards the back up to the midline, indistinctly keeled, folded over at the tip. ... Florets dark purple, palate split up to the middle, tips of the sections thickened. Pappus feathers widened spatulately at the tip. Pollen well developed. Achenia elongated and compressed, narrower at the base, dark brown.] 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.
Phylogeny
Internally, C. greimleri populations are more genetically distinct from one another than C. waldsteinii populations, whose intrapopulation diversity, however, is higher than C. greimleri. The high interpopulation diversity could have more to do with interspecific hybridisation, but it could also be solely the result of two effects of tetraploidy: one which slows genetic drift, and another which homogenises migrating populations more effectively, such as during recolonisation following the Last Glacial Period. The low intrapopulation diversity of C. greimleri could be thanks to differences in the severity of glaciation between the Alps and the Carpathians.
Externally, a close relationship between C. greimleri, C. waldsteinii, and C. hypoleucum is suspected on morphological grounds. The relationship between C. greimleri and C. waldsteinii has already been confirmed genetically, although an allopolyploid origin of C. waldsteinii is strongly suggested. The relationship between C. greimleri and C. waldsteinii is so close that the intraspecific differences between females and hermaphrodites are higher than the interspecific differences.
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