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Sisymbrium officinale (L.) Scop., Hedge Mustard

Account Summary

Introduction, archaeophyte, occasional and thinly scattered. European southern-temperate, but so widely naturalised it is now circumpolar.

1881; Stewart, S.A.; Co Fermanagh.

April to December.

Growth form and preferred habitats

The species is not very variable except in size and degree of hairiness, but it can appear either as a small, erect, simple stemmed rosette-forming annual with a slender taproot, or more commonly as a tall (60-90 cm), straggly and unevenly, stiffly branched biennial, which overwinters as a much larger basal rosette of deeply lobed leaves. The more hairy examples of the plant have as Grieve (1931, p. 570) points out, "a peculiar aptitude for collecting and retaining dust". The tiny lemon-yellow flowers overtopping the very distinctive, small, appressed fruits, and the straggling, tangled habit of the plant together readily allow definite identification of the species (Rich 1991).

In either growth form, Hedge Mustard is almost always found near habitation in both urban and rural situations. It grows on regularly disturbed, dry, open, sunny sites, over more or less fertile, moderately acid to calcareous or base-rich soils (Sinker et al. 1985; D.A. Pearman, in: Preston et al. 2002). Hedge Mustard is essentially a lowland species, almost always confined below 305 m (= 1,000 ft). Its stations are almost always closely associated with man's activities and the vegetation and soil disturbance that result (Salisbury 1964).

Fermanagh occurrence

Although Hedge Mustard has been recorded in 43 Fermanagh tetrads, 8.1% of the total in the VC, it is only occasional and sporadic and it never appears in any great quantity. Although most often found near habitation, it can also occur in more natural or semi-natural habitats along river and canal banks. However, even in these situations, in Fermanagh, it is generally found near bridges or along paths – ie beside another man-made feature! S. officinale has been recorded, however, in a definitely semi-natural setting on the Knockmore limestone cliffs, near the main woodland block on the slopes. We have almost no arable agriculture in Fermanagh, but before the advent of herbicides in other parts of the B & I Hedge Mustard was closely associated with such growing conditions.

Status

Although long regarded a native plant (eg Clapham et al. 1962; New Flora of the BI), this ruderal is now belatedly recognised as an archaeophyte (ie an ancient, accidental introduction), the only fossil record available to Godwin (1975, p. 136) being a seed excavated from a Roman well!

Flowering reproduction

Like many other weedy members of the Brassicaceae (the Cabbage family), reproduction is entirely by seed, flowering taking place from April to September, but with the main flush from mid-June to late July. The self-compatible flowers automatically self-pollinate, but are said to be occasionally visited by flies, hoverflies and small bees (Clapham et al. 1962; Proctor & Yeo 1973, p. 84), so there remains at least some possibility of crossing, even if it is only extremely rarely achieved.

Seed production

The very numerous pods or siliquae borne on a plant each contain an average of 15, small, light, wind-dispersed seeds and a large plant can produce more than 9,500 potential offspring (Ridley 1930; Salisbury 1964, p. 275).

Seed viability and longevity

Reports on the duration of seed longevity vary from transient to long-term persistent (that is, over five years), a not unusual picture of the available data obtained from the survey carried out on the topic in NW Europe by Thompson et al. (1997). However, experimental studies by Roberts & Boddrell (1983), listed in the mentioned survey, did show that in replicate experiments begun over four successive years, between 2.8% and 6.8% of seed sown remained viable and dormant after burial for five years (an average of 4.2%). This study also showed that most seedlings emerged in the field during the period March-September, with peak emergence often in July or August, some of the flushes following cultivation. Roberts & Boddrell (1983) pointed out that this pattern of predominantly summer emergence contrasted with other published data by Chancellor (1979), who found greatest emergence during March-June, with practically no seedlings appearing later. Montegut (1975) found that S. officinale germination occurred mainly in autumn and late winter.

These differing results highlighted the surprising fact that relatively little detailed study had previously been made of the basic biology and ecology of this very common weed, but during the last 20 years S. officinale has become, like Arabidopsis thaliana (Thale Cress), an important experimental organism and many research studies have been published on the complex physiological mechanisms and interacting factors controlling germination, dormancy and secondary dormancy in this species.

British and Irish occurrence

As an ancient introduction, Hedge Mustard has become very widespread in the British Isles (being found in 99% of VCs). However, the distribution thins decidedly, or is completely absent from, large areas of C and NW Scotland. It also becomes much less frequent in western parts of Ireland at all latitudes on the island (Preston et al. 2002). The reasons for this restricted distribution in B & I are not obvious since the range of the species in Europe extends very widely from the Mediterranean to around 62°N in Norway, and indeed as an introduction in the latter, it extends to almost 65°N.

European occurrence

S. officinale is believed to be native in Europe, N Africa and the Near East (Rich 1991), but being so closely associated with man, it really appears difficult to trace its true centre of origin. In the past, S. officinale occurred in Iceland as an introduction, but did not become established. It is commonly found and distributed well into continental E Europe and Russian parts of Asia (Jalas & Suominen 1994, Map 2129). In a scattered manner, it has been introduced and become naturalised both eastwards and southwards in many parts of the world, including China, Japan and W & E regions of N America. It is also naturalised in the southern hemisphere in extensive areas of S America, C & S Africa, Australia, Tasmania and New Zealand. It has been transported to very remote oceanic islands and become established in Hawaii and in the Falkland Islands (Hultén 1971, Map 253).

Uses

As the species name indicates, S. officinale has a history of use in herbal medicine, having the reputation of being an infallible remedy for the loss of voice. A strong infusion made from the whole plant used to be taken in the 18th century for all diseases of the throat, so that the French referred to it as the 'Singer's Plant' (Grieve 1931). The leaves have also been used as a green vegetable (Mabey 1996), although the plant has also been implicated in contact-dermatitis.

In recent years, forms of Hedge Mustard in some parts of the world have developed resistance to certain types of herbicide used to control broadleaved weeds and currently this is a subject of research interest. It is still possible to control it with hormone based herbicides provided they are applied at the seedling stage.

Names

The generic name 'Sisymbrium' is derived from the Greek 'sisymbrion' and was an ancient name referring to Watercress and possibly other species of the Brassicaceae, together with species of aromatic herbs of the Lamiaceae considered sacred to Venus (Gilbert-Carter 1964; Hyam & Pankhurst 1995).

The Latin specific epithet 'officinale' indicates that the plant was once listed as medicinal and sold by apothecaries in their 'shops' ('officina' in the singular) (Gilbert-Carter 1964).

The species has numerous English common names, several of which are far more interesting than the current boring 'Hedge Mustard'. They include 'Hedgeweed', or 'Bank Cress', from the frequently encountered hedge bank habitat of the plant. Prior (1879) includes 'Crambling Rocket' which he explains as being like, "a spurious Crambe or mustard, (as vetchling is a spurious vetch", plus the fact that the plant has, "leaves of rocket". Britten & Holland (1886) point out that one of the plant's synonyms was Eruca peregrina, so that there seems little doubt that 'crambling' is to be understood as a corruption of 'scrambling', or wandering 'rocket', and the name was also sometimes applied to quite a different plant, Reseda lutea (Wild Mignonette). Another interesting name listed by the latter authors is 'Lucifer Matches', which originated in Worcestershire, from the effect of the small clusters of pale yellow flowers resembling the sulphur used in the manufacture of matches (Melderis & Bangerter 1955). When the plant was introduced to Tasmania, the characteristic stiff, tangled side branches gave rise to the rather apt local name 'Wiry Jack' (Salisbury 1964).

Threats

None.