Picris hieracioides is a polymorphic species widespread in Europe and beyond, and its infraspecific taxonomy has been controversial up to the present. It has found to be a strictly allogamous species with a functional self-incompatibility system and is diploid with a basic chromosome number of x = 5, as is known from all species of
Picris (Slovák & al. 2007).
Morphological and genetic variation in European populations of
P. hieracioides as inferred from multivariate morphometric analyses and ALFP data does not corroborate the traditional infraspecific classification with its recognition of several subspecies, the circumscription of which has been rather controversial (Slovák & Marhold 2007; Slovák & al. 2012). Instead, both morphologically and genetically, only two infraspecific taxa can be distinguished (Slovák & Marhold 2007; Slovák & al. 2012): (1) one is largely restricted to higher altitudes (montane to alpine belt, rarely introduced to lower altitudes) across the European mountain ranges; it is found in montane to alpine tall herb communities, in supramontane to subalpine tall grass communities on relatively dry and warm slopes, in subalpine communities of deciduous shrubs, penetrating also in synanthropic habitats; its correct name is subsp.
umbellata. (2) the other is widespread in the lowlands to the submontane belt (and rarely introduced to higher altitudes) across Europe; it is found in a variety of open habitats such as dry xerothermous grasslands and disturbed synanthropic habitats (roadsides, railways, lowland river terraces, orchards, vineyards, etc.); it corresponds to the typical subspecies.
Two further taxa very closely related to
P. hieracioides are the Balkan coast endemic
P. hispidissima and
P. olympica from Turkey (Slovák & al. 2014, 2017). The former has been included as a third subspecies in
P. hieracioides (Slovák & al. 2014). A key to the identification of these subspecies is provided here under Keys.
Slovák & al. (2017) resolved in their molecular phylogenetic analysis a clade which they informally named the
Picris hieracioides group. Apart from the name-giving species, it comprises
P. olympica,
P. dahurica,
P. nuristanica, the E Asian
P. japonica,
P. junnanensis and probably also all other E Asian taxa, and the Australian taxa. The
P. hieracioides group evolved in the E Mediterranean-SW Asian region but a single evolutionary lineage of it managed to expand to E Asia and from their to Australia. The distribution of
P. hieracioides in E Asia as well as its relationship to and delimitation from its E Asian allies is in need of revision.
References
Slovák M. & Marhold K. 2007: Morphological evaluation of
Picris hieracioides L.
(Compositae, Lactuceae) in Slovakia. – Phyton (Horn) 47: 73–102.
Slovák M., Šingliarová B. & Mráz P. 2007: Chromosome numbers and mode of reproduction in
Picris hieracioides s.l.
(Asteraceae), with notes on some other
Picris taxa. – Nordic J. Bot.
25: 238–244.
Slovák M., Urfus T., Vít P. & Marhold K. 2009: The Balkan endemic
Picris hispidissima (Compositae): morphology, nucelar DNA content and relationship to the polymorphic
P. hieracioides. – Pl. Syst. Evol.
278: 187–201.
Slovák M., Kučera J., Marhold K. & Zozomová-Lihová J. 2012: The morphological and genetic variation in the polymorphic species
Picris hieracioides (Compositae, Lactuceae) in Europe strongly contrasts with traditional taxonomical concepts. – Syst. Bot.
37: 258–278.
Slovák M., Kučera J., Záveská E. & Vd'ačný P. 2014: Dealing with discordant genetic signal caused by hybridisation, incomplete lineage sorting and paucity of primary nucleotide homologies: a case study of closely related members of the genus
Picris subsection
Hieracioides (Compositae). – PLoS One 9(9): e104929.
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Slovák M., Kučera J., Lack H. W., Ziffer-Berger J., Melicharková A., Záveská E. & Vďačný P. 2017: Diversification dynamics and transoceanic Eurasian-Australian disjunction in the genus
Picris (Compositae) induced by the interplay of shifts in intrinsic/extrinsic traits and paleoclimatic oscillations. – Molec. Phylogen. Evol. 119: 182–195 // ➪ //