Additions to the flora of the Czech Republic. XII.

The twelfth part of floristic contributions includes newly published data of critically endangered species and data unpublished so far. Data of taxa newly discovered on the territory of the Czech Republic (Buglossoides incrassata subsp. incrassata, B. incrassata subsp. splitgerberi, Festuca pseudodalmatica, Sorbus barrandienica and S. omissa) and data of alien species found in the Czech Republic for the first time (Bromus bromoideus, Cotula coronopifolia, Euphorbia prostrata and bamboo Pleioblastus chino) are summarised. Furthermore, critically endangered species (according to the Red List of Vascular Plants of the Czech Republic) are reported from new sites (e.g. Agropyron pectinatum, Arabis nemorensis, Calamagrostis stricta, Cardamine parviflora, Carex chordorrhiza, Carlina acaulis subsp. caulescens, Cleistogenes serotina, Corrigiola littoralis, Drosera intermedia, Epipactis moravica, Erica tetralix, Filago lutescens, Herniaria hirsuta, Juncus gerardii, Listera cordata, Lycopodiella inundata, Myosotis stenophylla, Orchis morio, Ornithopus perpusillus, Polycnemum arvense, P. majus, Potentilla rupestris, Salix myrsinifolia, Tillaea aquatica and Urtica kioviensis). Finally, less rare and threatened species are reported from areas where they had not been recorded yet (Cephalanthera longifolia, Epipactis microphylla, Leersia oryzoides, Phegopteris connectilis, Pyrola media, Stellaria palustris). Examination of herbarium material of alien grasses revealed six species new to the Czech Republic: Chloris pectinata, Ch. divaricata, Eleusine coracana subsp. coracana, E. tristachya, Leptochloa decipiens subsp. peacockii and L. divaricatissima. These all occurred in this country as casuals, most of them introduced with wool of Australian origin. In contrast, re-identification of herbarium vouchers has showed that the following species were mentioned in the literature for the Czech Republic erroneously: Chloris radiata, Enteropogon acicularis (syn.: Chloris acicularis), Eriochloa punctata, Leptochloa panicea s.l. (incl. L. mucronata and L. filiformis) and Sporobolus indicus. No specimen of Chloris pycnothrix was seen in the studied herbarium material, so that the occurrence of this species in the Czech Republic is doubtful.