Lepidium

Rūrāne, Ieva & Roze, Ieva, 2019, Genus Lepidium L. In The Flora Of Latvia, Acta Biologica Universitatis Daugavpiliensis 19 (2), pp. 191-198 : 196

Lepidium is a morphologically well-separated

genus. Evaluating morphological features of Lepidium it can be concluded that the most important are leaf form, fruit shape and fruit with or without wing.

Lepidium species distribution in Latvia mainly is related to anthropogenic habitats. Species occur on railway embankments, railway tracks, weed-laden sites, roadsides, landfills as well as a weed in gardens. From all Lepidium species in Latvia only L. ruderale is native and is distributed throughout the territory rather rare. Distribution mainly is related to cities and other populated areas.

Among 150 most widespread alien plant species in Europa L. densiflorum , L. sativum and L. virginicum are included ( Lambdon et al. 2008). The most common alien species of Lepidium is L. densiflorum . After herbarium material revision it is concluded that L. densiflorum has been found already in 1911 and 1912 in Riga by R. Seidenberg. In the period till 1940 L. densiflorum was found in three localities. In the period from 1941 to 1990 L. densiflorum has spread rapidly and is found mainly in large cities in the Central and Eastern part of the territory. Localities in large cities and in surrounding of them also remain in the period from 1991 to the present. L. densiflorum nowadays after herbarium material data is found rare. L. densiflorum is widely naturalized in Europe ( Vasconcellos et al. 1993), Poland ( Tokarska-Guzik et al. 2010), Romania ( Sîrbu et al. 2014). In Lithuania L. densiflorum also is considered as naturalized species and is distributed in the whole territory ( Gudžinskas 1997). In Estonia, L. densiflorum is alien species which occurs rare on the railway and near settlements ( Kukk & Kull 2005).

As confirmed by herbarium data two species are found very rare – L. virginicum in 1913 and L. pinnatifidum in 1961. Distribution of L. campestre is related to railways and weed-laden sites and as rare species is found throughout the territory. L. sativum is grown in gardens and very rare is found in the wild. L. perfoliatum and L. latifolium distribution are related to Coastal Lowland and only some individuals are found in the Eastern part of Latvia in Daugavpils.