Erysimum cheiri (L.) Crantz, Wallflower
Account Summary
Introduction, archaeophyte, a very rare garden escape or discard.
1980; Northridge, R.H.; on an old wall in the W of Enniskillen town.
Growth form, preferred habitats and likely Centre of Origin
Nowadays, this is a rather unfashionable garden perennial, but it is a colourful, traditional subject nevertheless and has been in continuous horticultural use in B & I since at least the 13th century (Harvey 1990). The Wallflower's garden popularity may possibly extend right back to the Roman period in Britain, since the species, which is considered a native of Greece and the E Mediterranean is very probably of hybrid origin (Snogerup 1967). Garden varieties are very variable in flower colour and size, but naturalised plants usually lie within the yellow, red or orange spectrum (Rich 1991). The plant readily naturalises itself on walls, cliffs and rocks when introduced to fresh territories throughout C, W & S Europe.
British and Irish occurrence
Naturalisation of E. cheiri commonly occurs in the southern two thirds of Britain and in most of Ireland, but the species becomes rare and decidedly coastal the further north one travels, which suggests it is near its lower temperature limit (Garrard & Streeter 1983; Clement & Foster 1994; Preston et al. 2002). Having said that, the New Atlas hectad map indicates a presence just N of Inverness (VC 106)!
Reynolds (Cat Alien Pl Ir) lists E. cheiri as being recorded at least once (but sometimes indeed just that), from 33 of the 40 Irish VCs, which does not include Fermanagh (H33).
Fermanagh occurrence
As far as the current author can tell, E. cheiri only very rarely escapes from gardens in the county. One of the only two records in the Fermanagh Flora Database (both discovered by RHN) was indeed growing in the lime mortar of an old wall in Enniskillen. The second record was found in Newtownbutler village in 1988. In the FNEI 2, Praeger commented that in Cos Down (H38) and Antrim (H39), Wallflower showed a distinct preference for ancient walls, eg those in castles and tower houses. This reflects the affinity the species has for calcareous substrates (Rich 1991), the preference being met by the crumbling lime mortar of these types of old walls.
The paucity of E. cheiri records in Fermanagh is probably misleading, but the extent of any under-recording due to prejudice against introductions is unknown. We believe that earlier recorders (including many who were employed on conservation surveys from the 1960s onwards), considered garden escapes and other aliens as transient, casual organisms of no conservation significance and therefore unworthy of note. If this was their thinking they would be doubly wrong: E. cheiri is a perennial with a woody stem base which makes it not only tolerant of dry soils of very indifferent fertility, but also allows it, once established, to be remarkably persistent − always provided the most essential growth requirements of the species are met − a warm sunny spot with little competition.
European and world occurrence
Having been in cultivation for many centuries, the precise origin of this species is unknown, but very probably E. cheiri is of hybrid origin, linked to several Aegean species. E. cheiri is mapped as an archaeophyte introduction across parts of W Europe − mainly in France, C Italy, Britain & Ireland. The distribution becomes increasingly scattered southwards towards the Mediterranean basin and it is absent from Denmark, Scandinavia and all of N & E Europe (Jalas & Suominen 1994, Map 2172).
Threats
None.