Scrophularia nodosa L., Common Figwort
Account Summary
Native, frequent to locally common. Eurosiberian temperate, introduced in eastern N America.
1881; Stewart, S.A.; Derrygonnelly.
Throughout the year.
Growth form and preferred habitats
A stout, erect, unbranched perennial, growing 60-120 cm tall, from a rhizome or rootstock that is tuberous and covered with numerous 'knotted' nodules – hence one of its English common names 'Knotted Figwort', and its Latin specific epithet 'nodosa', meaning 'swollen joints'. This underground organ, which today we usually are forbidden to excavate and examine for conservation reasons, is very well illustrated by Ross-Craig (1966, Part XXII, plate 16). The glabrous stem is sharply four-angled, dull green and finely speckled with purple. The opposite leaves are stalked, glabrous, 5-12 cm long, dark, slightly bluish-green on the upper surface, paler beneath, ± triangular ovate, acute at apex. The leaf margins are coarsely and unevenly or doubly toothed, with larger teeth occurring towards the base (Hutchinson 1972; Sell & Murrell 2007).
S. nodosa differs from S. auriculata and S. umbrosa in the sharply four-angled, but un-winged stem and the very narrow scarious border of the sepals (Garrard & Streeter 1983).
S. nodosa is a quite frequent but non-gregarious, often local perennial of shaded or semi-shaded, moist to damp, but well-drained, fertile soils in a wide variety of lowland sites, some of which are disturbed, eg along roadsides, ditches, hedgerows, waste ground and quarries (Garrard & Streeter 1983; Sinker et al. 1985). It is chiefly found as more or less isolated plants in woods along their margins and rides, and in scrub, often on lakeshores, streamsides or river banks, but it is also less frequently found in drier situations on screes and along lanes, gravel driveways and on waste ground. While it tolerates a considerable degree of shade (Halliday 1997), it can also grow on walls at heights of 3-4 m above the ground (Ridley 1930).
S. nodosa was included by Salisbury (1942) with a list of 16 other, "woodland types characteristic of intermittently open habitats" that for instance included Chamerion angustifolium (Rosebay Willowherb), Cirsium palustre (Marsh Thistle), Digitalis purpurea (Foxglove), Galeopsis tetrahit (Common Hemp-nettle), Gnaphalium sylvaticum (Heath Cudweed), Hypericum perforatum (Perforate St John's-wort), Senecio sylvaticus (Heath Groundsel) and Verbascum thapsus (Great Mullein). The 17 species on Salisbury's list all tend to be common features of coppiced areas or clearings in recently felled woodland and they share the characteristic of sometimes occupying such temporary open areas in amazing abundance, almost certainly due to the presence of their dormant seed in the woodland soils. Species that occupy habitats that are only intermittently available for colonisation tend to have much larger seed productivity, for instance, 38 of these species produced approximately 28,200 seeds per plant, compared to 38 species of permanently open habitats that produced just over 3,000 seeds per plant (Salisbury 1942).
A successful, competitive perennial species that holds its ground well, Common Figwort features in the tall herb community of damp ground, but it is intolerant of both grazing and mowing (Sinker et al. 1985). However, the leaves are bitter-tasting so that browsing animals normally avoid it entirely. "Cattle, as a rule, refuse to eat the leaves as they are bitter, acrid and nauseating, producing purging and vomiting if chewed."(Grieve 1931).
The established strategy of S. nodosa is characterised by Grime et al. (1988, 2007) as C/CR, meaning it is intermediate between a straight Competitor species and a Competitive Ruderal.
Flowering reproduction
S. nodosa flowers in summer and early autumn, from July to October. The flowers are borne in loose, pyramidal panicles composed of small opposite to alternate cymes, the oldest flowers being in the middle of each cyme. The branches of the inflorescence are covered with short gland-tipped hairs.
The flowers are bisexual, 6-7 × 3-4 mm, the calyx saucer-shaped, 5-lobed, the lobes ovate with short teeth on the margins. The sepal margins have a very narrow, often scarcely visible, scarious margin. The corolla is irregular, 2-lipped, 7-10 mm, the tube greenish and the upper lip purplish-brown, 2-lobed. The lower lip of the corolla is greenish, 3-lobed and shorter than the upper lip. There are four fertile stamens plus a solitary sterile staminode that is broader than long and is emarginate (ie slightly notched). The fertile stamens are at first curled downwards, away from the style which matures first and occupies the mouth of the corolla (ie the flower is protogynous). The ovary, which is seated on a large, fleshy, nectar-secreting receptacle disk, is 2-locular, with numerous ovules on the two fleshy axile placentas (Butcher 1961; Hutchinson 1972; Sell & Murrell 2007).
Pollination
Cross-pollination is effected primarily by wasps of the genus Vespula, and by flies, the brownish-purple petal colour being typical of 'wasp-flowers'. The insects are attracted by the carrion-like smell of the flowers. The stigmas are receptive before the anthers open and they remain so for 48 hours. After this, the stamen filaments straighten, the pollinated stigma withers and the style bends down over the lower lip of the corolla, its place being taken at the mouth of the corolla by the discharging anthers. Insect visitors alight on the upper, younger flowers that are in the female phase and work their way downwards to the older flowers that have moved to the male phase, thus carrying out cross-pollination.
The fruit is a broadly ovoid, pointed capsule containing many rugose (rough textured), brown seeds 1.2 × 0.6 mm, that are half ovoid, marked with deep vertical grooves and horizontal striae. The capsule opens by splitting into four valves and the small seeds are shaken out by wind or by passing animals moving the plant (Butcher 1961; Hutchinson 1972).
Seed production
In terms of fruit and seed production, Salisbury (1942) examined 61 plants and found the number of fruits ranged from 42 to 956 per plant. The total number of capsules counted was 14,354, giving a mean of 235 ± 16 capsules per plant. Sixteen capsules were examined for seed content and the number of seeds per capsule ranged from 105-272. The mean number of seeds in the 16 capsules was 204 ± 8.6. Thus the mean seed output per plant per year was between 43,000 and 54,000 seeds. Germination in the light is around 60%, so the calculated mean reproductive capacity would be around 28,000 potential offspring each year (Salisbury 1942).
Salisbury (1942) does mention that another researcher, Eklund (1929) in Scandinavia, produced data for six capsules of S. nodosa which yielded a much lower average, namely 105 seeds per capsule. Eklund also gave the numbers of fruits for two individuals as 60 and 76. As Salisbury (1942) commented, these data would, if typical, suggest a much lower productivity in Scandinavia than in his own studies in Britain.
Seed dispersal and longevity in soil
There is no specialised seed dispersal mechanism, but the tall plants provide a favourable starting point for wind to catch and carry the small, lightweight propagules at least a few metres from the parent fruit capsule. As mentioned above, S. nodosa has often been observed growing on walls in elevated positions (up to 3-4 m) (Ridley 1930, p. 28), clearly carried aloft by wind.
The seed is also long-term persistent in the soil seed bank, some of it remaining viable for at least five years (Thompson et al. 1997).
Vegetative reproduction
There is evidence of vegetative reproduction in S. nodosa from an examination of the swollen underground rhizome or tuber and its nodules. Salisbury (1942) contrasted the rapid vegetative extension growth of Ranunculus repens (Creeping Buttercup) runners with what he referred to as, "the closed type of extension growth of S. nodosa" involving very small annual increments in the spread of the underground tuber over an eleven year period of study (Salisbury 1942, pp. 225-6, Fig. 35). This 'closed extension of growth' is described by him as, "owing to the swollen character of the short stolons and their perennial character, almost complete exploitation within the periphery is assured."
Fossil history
There are no fossil pollen records for S. nodosa and Godwin (1975) reports a solitary seed identification by Reid from the Hoxnian interglacial. Thus there are no fossil records of any sort from the present interglacial in either Britain or Ireland that the current author (RSF) has information about. This does not decide native or introduced status, but it means that all and any available evidence regarding status will be circumstantial, and needs to be carefully analysed.
Fermanagh occurrence
Although seldom if ever plentiful, as the tetrad map shows, S. nodosa is fairly frequent and very widespread in Fermanagh, having been recorded in 209 tetrads, 39.6% of the VC total.
British and Irish occurrence
Widely distributed throughout B & I, except for N Scotland, the Scottish Highlands and the NW of Ireland where the soils are probably too acid and peaty for it (New Atlas). There is little evidence of any significant change in the distribution or frequency of S. nodosa from BSBI surveys covering the period since the 1960s (Braithwaite et al. 2006).
European and world occurrence
Eurosiberian temperate in its phytogeography, widespread in Europe and W Asia, but noticeably thinning towards both north and south in Scandinavia and the Mediterranean (Hultén & Fries 1986, Map 1631). It is rarely recorded in eastern N America, where it is an introduction, and it has also been introduced to South Island, New Zealand where it is very rare (Webb et al. 1988).
Uses
Common (or Knotted) Figwort has a long history of herbal and folk medicine uses, the 'fig' in the name referring to piles. This brown-flowered and very smelly herb has knobbly, tuberous roots (hence the alternative common name), which by the 'doctrine of signs' suggested its use for treating the disease called 'scrophula' (or 'scrofula'), that was characterised by glandular swellings and probably was a form of tuberculosis. The disease was formerly also referred to as 'the King's Evil', characterised by swollen tubercular glands on the neck (Grigson 1955, 1987). S. nodosa was called 'the Scrofula Plant' on account of its value in treating all forms of cutaneous eruptions, abscesses and wounds and it was formerly considered a specific for this purpose (Grieve 1931; Stearn 1992). The flowers also have small glands on the corolla, which being far more visible than the tuber, might also suggest the species' connection with Scrophula or Scrofula disease (Gledhill 1985).
In herbal medicine, the plant is considered to possess diuretic and anodyne properties, ie it helps produce urine, or assists its flow and is painkilling. The whole herb, collected fresh and dried in June and July, is made into a decoction for external use, and the fresh leaves are also made into an ointment (Grieve 1931). In Ireland, the dried root or tuber was ground to a powder and mixed with lard to make an ointment used for treating piles and all kinds of skin troubles. The roots and leaves, and sometimes the seeds, were boiled and the liquid drunk as a kind of tonic, "held to clear the blood of impurities, including boils and rashes". The forerunning examples and numerous other Irish herbal medicinal applications are detailed by Allen & Hatfield (2004).
British use of this herb has been very slight in comparison with Irish use and apparently has been restricted to the leaves alone, for poulticing skin eruptions, abscesses, ulcers and wounds (Allen & Hatfield 2004).
Of all the different species of Figwort, S. nodosa is the most used, principally as a fomentation for sprains, swellings, inflammation, wounds and diseased parts, especially in scrofulous sores and gangrene (Grieve 1931).
Names
The genus name 'Scrophularia' is from the Latin 'scrofule', translating as 'scrophula', the tubercular disease it was supposed to cure. The Latin specific epithet 'nodosa' means 'having conspicuous joints or nodes', or 'knotty', ie referring to the root tuber and its nodules (Gilbert-Carter 1964; Gledhill 1985; Stearn 1992).
Grigson (1955, 1987) reported that in Ireland, Figwort was considered the 'Queen of Herbs' and Foxglove 'the King of Herbs'. He lists a total of 15 additional English common names for the species, several of which refer to the greenish-brown tint of the leaves and the brown colour on the petals, such as 'Brown-net', 'Brownwort', 'Brunnet' and 'Brennet'. A few of the names refer to the medicinal properties of the herb, such as 'Poor Man's Salve' and 'Cut-finger'. Several names refer to the unpleasant smell of the plant, such as 'Stinking Christopher' and 'Stinking Roger' (Grigson 1955, 1987).
Threats
None.