Kniphofia x praecox  

Kniphofia ×praecox Baker (=? K. uvaria (L.) Oken × K. bruceae (Codd) Codd × K. linearifolia Baker) (Cult.) – An exceptional escape from cultivation or, more likely, established throw-out. A single well-established population is known from a railway siding in Wervik. It was discovered in 2015 but is obviously present since several years (already visible on Google Streetview images from 2010). It forms a dense monospecific stand that easily survives periodical herbicide treatments.

Characteristic features of this population are its early flowering (June), high sterility, leaves ca. 40 mm wide with minutely toothed margins, etc. This corresponds well with Kniphofia ×praecox (e.g. Jäger & al. 2008, pro species). This taxon appears to be one of the ‘usual’ escapes of the genus in the British Isles as well (Stace 2010; see also here for its distribution there: http://bsbi.org/maps/?taxonid=2cd4p9h.7c5).

Surprisingly, Kniphofia ×praecox is often left unmentioned in horticultural overviews (e.g. Droop 1986, Whitehouse 2010).

Selected literature:

Jäger E.J., Ebel F., Hanelt P. & Müller G. (eds.) (2008) Rothmaler Band 5. Exkursionsflora von Deutschland. Krautige Zier- und Nutzpflanzen. Springer Verlag, Berlin: 880 p.

Stace C. (2010) New flora of the British Isles, 3th ed.: XXXII + 1232 p. Cambridge University Press.