Symphytum officinale L., Common Comfrey

Account Summary

Growth form and preferred habitats

This vigorous perennial, has a branched rootstock that is thick, fleshy and tuber-like. From this arises erect, branched stems 10-150 cm tall, bearing large, ovate-lanceolate, entire leaves, 15-25 × 1-8 cm, bristly hairy (ie setose) and very rough to the touch. Stem leaves are smaller, sessile, the leaf base strongly decurrent, forming wings on the stem that extend down more than one internode. It flowers in late April or early May onwards, the inflorescence being a terminal, bract-less, scorpioid (ie curled) cyme of pendulous, bisexual flowers. The bell-shaped, campanulate corolla is variable in colour, usually pale- or creamy-yellow, but it can also rarely be purplish or pink, or occasionally striped dark and light purple, rarely white making identification from the more tubular, but very variable hybrid, S. × uplandicum (Russian Comfrey) somewhat more difficult (F.H. Perring, in: Rich & Jermy 1998; Sell & Murrell 2009; Stace 2019). The flowers are insect pollinated and the ripe fruit nutlets are smooth and shining (Garrard & Streeter 1983; Parnell & Curtis 2012).

There are just two estimations of seed longevity in the survey of soil seed banks of NW Europe and they both indicate the seed is transient, surviving one year or less (Thompson et al. 1997). The roots are very brittle and the plant can regenerate very quickly, even from a very small portion of root (Grieve 1931).

Across B & I, S. officinale appears to prefer damp or wet waterside habitats with fertile, neutral or lime-rich soils. These include fens, marshes, river-, stream- and canal-banks, as well as beside wet ditches and on damp roadside verges (Garrard & Streeter 1983; D. Welch, in: Preston et al. 2002). The species is vigorously competitive and it can quickly develop a sizeable clonal clump of vegetation in sun or half-shaded, sheltered situations. It is intolerant of grazing (Sinker et al. 1985; Ellis 1993).

Occasional planted in an ornamental garden setting, although much more often the hybrid S. × uplandicum is the preferred planted subject, S. officinale is not fussy regarding soil type, provided it is neither too dry nor too greatly disturbed. Having said this, once introduced to a garden, it is very difficult to subsequently extirpate it on account of its vigorous vegetative reproductive ability.

Nowadays, Comfrey is frequently grown as a useful manure yielding plant. The plant tissues are rich in minerals including potassium, phosphate and calcium. Cut stems are steeped in water for around four weeks and the resultant liquid used as a plant fertiliser, especially beneficial for the growth of soft fruit and potatoes. Comfrey is also useful as an accelerator for compost making (https://mantis.uk.com/nettle-comfrey-perfect-organic-treatment-spring/#:~:text=Comfrey%20manure%20accelerates%20cell%20division%2C%20favours%20flowering%20and,plants%20such%20as%20red%20berries%2C%20tomatoes%20or%20potatoes, accessed 16 February 2022).

The established strategy of the species is categorised as C/CSR, ie intermediate between a Competitor and a more general non-specialist Competitor-Stress-tolerant-Ruderal (Grime et al. 1988, 2007).

Variation

Two subspecies are recognised in Flora Europaea 3, subsp. officinale with the leaves typically decurrent down the stem, and subsp. uliginosum (A. Kerner) Nyman, with leaves, even the uppermost, not or shortly and narrowly decurrent. Subsp. uliginosum is confined to east central Europe whereas subsp. officinale is more widespread (B. Pawlowski, in: Tutin et al. 1972). On the other hand, Sell & Murrell (2009) feature two varieties, described as var. officinale (= S. officinale var. purpureum Pers.), with flowers purplish or pink, and var. ochroleucum DC. with flowers white or creamy-yellow, sometimes tinged purplish.

Stace (2019) also recognises two subspecies, subsp. officinale, often >1m tall, corolla >16 mm, variable in colour – cream, purplish or sometimes striped dark and light purple, rarely white; and the much rarer, very restricted, subsp. bohemicum (F.W. Schmidt) Čelak., stems shorter, usually <1m, corolla <16 mm, pale cream.

The Royal Horticultural Society's Index of garden plants (Griffiths 1994) describes the flower colours as white, pink or purple-violet and lists cultivars of subsp. officinale as cultivar 'Bohemicum' to 30 cm, flowers off-white, occasionally tinged purple, and cultivar 'Variegatum' with leaves edged white and cream, flowers cream, but red in bud. The Index also mentions subsp. uliginosum, describing it as, "stem and leaves sparingly setose, densely verrucose-hispid".

Fermanagh occurrence

S. officinale has been recorded in 36 Fermanagh tetrads, 6.8% of those in the VC. It is occasional and widely scattered throughout the county, but it is principally associated with out-of-the-way stream-sides and waste places where garden refuse is discarded. The tetrad map shows that it is particularly frequent along the Colebrooke River and its tributary streams. It is also found in rough grass in damp meadows and along roadside verges.

S. officinale is just possibly native along some streams and rivers in the VC, but it more frequently and more widely occurs as an established alien, largely due to the deplorable, yet very common practice of unauthorised, illegal dumping of garden waste in semi-concealed sites. All too often, this dumping occurs over bridges, in ditches or on bog margins in rural districts. Discarded tubers may then spread the species downstream along these various waterways. Trade and transport of top soil may provide a secondary means of dispersal for tubers of S. officinale, and the species can persist for many years and develop large clonal patches in a variety of damp to wet, rough ground habitats.

British & Irish occurrence

In field recording, S. officinale is often confused with the more commonly planted S. × uplandicum, so that the data available in both BSBI Atlases (Perring & Walters 1962; Preston et al. 2002) need to be viewed with the possibility of this confusion and that S. officinale has been over-recorded borne in mind. Having said this, the New Atlas hectad map shows S. officinale as being locally frequent and widespread across damp to wet habitats in lowland parts of Britain from Cornwall to Inverness. Fossil evidence is scant or non-existent at the species level (Godwin 1975) and the native area of S. officinale in B & I is unknown. The species may well be an alien garden introduction across N & W Britain and in Ireland, although the map depicts it as native everywhere (D. Welch, in: Preston et al. 2002).

When considering status, it is important to bear in mind that Comfrey has a long association with folklore and medicinal herbal use (see under Russian Comfrey below).

European and world occurrence

The species is considered to have originated in SE Europe and W Asia and since it was primarily used as a herbal medicinal plant cultivated in gardens, it has been spread widely by man into N Europe (including Iceland and N Scandinavia), eastern N America and New Zealand (Hultén & Fries 1986, Map 1546).

Names and uses

The genus name 'Symphytum' is from the Greek 'symphy-' meaning 'growing together' (Gledhill 1985), a reference to the wound-healing medicinal properties of the herb known to Dioscorides and herbalists since Classical times. The Latin specific epithet 'officinale', refers to the herbalist's 'office' or pharmacy.

There are numerous English common names for the herb, 13 in Britten & Holland (1886), 12 in Grieve (1931), 10 in Grigson (1955, 1987) and 14 in Vickery (2019) and they do not all repeat one another and overlap! Most of the names refer to the knitting together of wounds including broken bones, eg 'Knitbone' and 'Boneset', the leaves being bandaged over the break (Vickery 2019). The name 'Comfrey' is a corruption of 'con firma' in allusion to the uniting or knitting of bones (Grieve 1931). The plant was also used in various ways to ease the pain and heal sprains, bruising, arthritis, skin ulcers, boils, cuts and grazes (Vickery 2019). The chief constituent of Comfrey is mucilage which it contains in abundance. It is also mildly astringent and an expectorant. It was used as a demulcent in treating lung troubles and for quinsy and whooping cough (Grieve 1931).

The name 'Abraham, Isaac and Jacob' given by Grigson (1955, 1987) refers to the variation in colour of the flowers, but other names he lists, such as 'Church Bells', 'Coffee Flowers', 'Snake' and 'Gooseberry Pie' appear more obscure. The latter name was also given to Epilobium hirsutum (Great Willowherb), apparently a reference to the smell of the leaves (Britten & Holland 1886).

In the past, the plant was widely recommended as a green food for most animals and was said to be both preventive and curative of foot and mouth disease in cattle. If grown as a crop for harvest, it could produce sufficient growth for two large cuts per year. It was found that horses, cattle and pigs would eat Comfrey, but they never took kindly to it as forage. Pigs took best to it as fodder in the green state, but even they took some time to get used to it. The feeding value of Comfrey proved little better than grass and the species is not adapted for growth on dry or poor land, so its use as a fodder crop was brief (Grieve 1931).

Threats

None.

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