66 research outputs found
Limonka Gmelinova (Limonium gmelinii) na dálnicích České republiky
The paper describes finds of Limonium gmelinii on the D1 and
D2 motorways in southern Moravia (south-eastern part of the
Czech Republic). Limonium gmelinii is a plant of continental
halophytic vegetation, such as saline steppes and marshlands,
with a large distribution range extending from south-eastern
Europe over southern Ukraine, south-eastern European Russia
to southern Siberia in the east and some parts of Central
Asia in the south. It is reported here for the first time as
a naturalized alien species of the Czech flora. Until now it
has been known from four sites, of which one is situated on
the D1 motorway near the village of Ostrovačice, west of the
city of Brno (first recorded by J. Danihelka in 2009), and
three on the D2 motorway southeast of Brno, near the villages
of Otmarov, Opatovice and Rakvice (first recorded by P.
Kocián in 2013 but already recognizable on Street View
photographs of Google Maps from August 2009). The Ostrovačice
site, harbouring a single specimen, is the only place where
L. gmelinii is found at the road verge under steel beam
barriers. At the remaining three sites, in contrast, plants
are always found in the central reservation. While the
population near Rakvice consists of up to 40 flowering
specimens, the populations near Opatovice and Otmarov are
less numerous, consisting of about 5 and 2 flowering
individuals, respectively. The identification of our
specimens (deposited at BRNU and OL) as L. gmelinii seems to
be almost certain; however, we refrained from identification
to the microspecies level (as L. hungaricum or L. hypanicum,
both described by M. V. Klokov) because the infraspecific
variation of L. gmelinii is insufficiently known. We assume
that the seeds of L. gmelinii were introduced to the Czech
motorways via international traffic from Hungary but this
assumption is based solely on geographic considerations and
cannot be supported by any other arguments. This may have
happened as soon as in the early 2000s, and now the species
seems to be naturalized and about to spread. However, it will
most likely remain confined to motorway central reservations
and verges of main roads because of its specific habitat
requirements
A Multigene Phylogeny of Native American Hawkweeds (<i>Hieracium</i> Subgen. <i>Chionoracium</i>, Cichorieae, Asteraceae): Origin, Speciation Patterns, and Migration Routes
Native American hawkweeds are mainly mountainous species that are distributed all over the New World. They are severely understudied with respect to their origin, colonization of the vast distribution area, and species relationships. Here, we attempt to reconstruct the evolutionary history of the group by applying seven molecular markers (plastid, nuclear ribosomal and low-copy genes). Phylogenetic analyses revealed that Chionoracium is a subgenus of the mainly Eurasian genus Hieracium, which originated from eastern European hawkweeds about 1.58–2.24 million years ago. Plastid DNA suggested a single origin of all Chionoracium species. They colonized the New World via Beringia and formed several distinct lineages in North America. Via one Central American lineage, the group colonized South America and radiated into more than a hundred species within about 0.8 million years, long after the closure of the Isthmus of Panama and the most recent uplift of the Andes. Despite some incongruences shown by different markers, most of them revealed the same crown groups of closely related taxa, which were, however, largely in conflict with traditional sectional classifications. We provide a basic framework for further elucidation of speciation patterns. A thorough taxonomic revision of Hieracium subgen. Chionoracium is recommended
Diploid Chromosome Numbers in Hieracium and Pilosella (Asteraceae) from Macedonia and Montenegro
The authors report the first discovery of diploid populations of Hieracium naegelianum Panč. subsp. naegelianum and H. naegelianum subsp. ljubotenicum Behr & Zahn., and give the first chromosome counts for H. cernuum Friv., H. gymnocephalum Griseb. ex Pant., H. sparsum Friv., Pilosella pavichii (Heuff.) Holub and P. serbica (F. W. Schultz & Schultz-Bip.) Szeląg from Macedonia and/or Montenegro. A diploid chromosome count for Hieracium renatae Szeląg is confirmed based on material from the whole distribution range of the species. An emasculation experiment showed that all the analyzed diploid Hieracium taxa reproduce sexually
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