Symphytum officinale × S. asperum
(S. × uplandicum Nyman), Russian Comfrey
Account Summary
Introduction, neophyte, garden escape, occasional.
1939; Praeger, R.Ll.; Newtownbutler.
April to November.
Rather surprisingly, in view of the (at least) eight toxic alkaloids it contains, this erect, much-branched perennial up to 1.5 m tall was introduced and cultivated in gardens as a decorative plant in the early 19th century and certainly by 1827 (Cooper & Johnson 1998; Stace et al. 2015). In addition, hybrid material was introduced from Sweden by the agronomist, Henry Doubleday, and enthusiastically promoted and marketed as the forage crop 'Russian Comfrey'. As food, the bristly hairy plant proved unattractive to most farm animals, with the possible exception of pigs (Grieve 1931). It was first recorded in the wild at Marlborough, N Wiltshire, in 1861 (Wade 1958). These plants, together with further introductions, gave rise to many naturalised populations across B & I.
S. × uplandicum is a hybrid between the possibly native S. officinale (Common Comfrey) and the definitely introduced, sky-blue flowered, S. asperum (Rough Comfrey) which originated in NE Turkey, the Russian Caucasus and Iran. The hybrid is still found naturalised around farms and remains cultivated in many gardens, it is just a little more frequent and widespread than Common Comfrey in Fermanagh. Being closely related, Common- and Russian Comfrey both occur in very similar ecological situations, ie in damp, rough ground where garden material is deposited, along stream-sides, roadsides, waste ground, dumped soil and on woodland margins. The hybrid can form dense, often rather uniform stands on damp, fertile soils in these types of habitats (Stace et al. 2015).
In Fermanagh, S. × uplandicum has been recorded in 40 tetrads (7.6% of those in the VC. As the tetrad distribution map shows, it is widely scattered, but is chiefly found in the lowlands E of Lough Erne. Although S. × uplandicum readily establishes and persists, it does not appear to spread to any great extent. This hybrid has been recorded in 35 of the 40 Irish VCs (Cat Alien Pl Ir) and probably it is still being introduced to new areas and is also spreading itself to some limited extent.
The hybrid can be distinguished from S. officinale by the stem leaves being less decurrent than in the species, ie the wings on the petiole and stem of the hybrid do not extend below the next leaf down the stem. The flower colour of the hybrid is also more variable, either pinkish-blue, violet or purplish or starting rose, turning bluish, or whitish, ± tinted pale rose and blue (Sell & Murrell 2009). Despite the corolla colours of the parent species, surprisingly the hybrid never has the blue or reddish-purple that they display, nor the cream colour of S. officinale. Moreover, the flowers of S. × uplandicum often change colour as they mature, turning from more reddish to more bluish (Stace et al. 2015).
There is no conclusive evidence for the in situ production of S. × uplandicum F1 hybrids in the wild in B & I. However, S. × uplandicum does backcross with S. officinale and produce a range of intermediate plants that complicate identification to some degree (Stace et al. 2015).
The hybrid distribution in B & I, as shown in the New Atlas hectad maps, is now quite independent of its parents and is considerably more extensive than the occurrence of S. officinale, while S. asperum is very rare (D. Welch, in: Preston et al. 2002). Unfortunately, identification confusion between S. officinale and S. × uplandicum has led to an unknown degree of over-recording of the former and this needs to be borne in mind when comparing maps (D. Welch, in: Preston et al. 2002; Stace et al. 2015).
Like other Comfreys, the plant has long been valued by herbalists for treatment of bruises, sprains and arthritis, and as a general wound master-healer. More recently, Russian Comfrey has been favoured by organic gardeners who grow it, and then cut and steep the foliage for up to a month to produce a liquid manure, or else dig the foliage into the soil, or add it to developing compost heaps in order to accelerate the decomposition process (Vickery 1995; Mabey 1996).
Fermanagh Occurence
Threats
None.