Hypericum androsaemum L., Tutsan

Account Summary

Growth form and preferred habitats

A highly variable, perennial, lowland, stout, bushy subshrub 30-100 cm tall, with brownish-red erect or spreading shoots arising from a woody rootstock. Stems are ± round, but when young have two raised lines or ridges running lengthwise. Tutsan plants retain at least some of their paired, large, oval, obtuse leaves during our relatively mild oceanic winters and thus in W Ireland the species is a semi-evergreen, opposite-leaved plant.

Although there are more garden-worthy species and forms of the genus Hypericum available from horticultural suppliers, plants indistinguishable from the 'wild form' of H. androsaemum are regularly planted in gardens for their rather large yellow flowers with prominent yellow stamens in four or five bundles and colourful, fleshy, berry-like fruit capsules. If, as very likely is the case, non-local forms 'escape' over the garden wall, the distribution of the native population inevitably becomes obscured. The shrubby Hypericum species that occur in Britain & Ireland all have four or five separate bundles of 10-25 stamens on long slender filaments that help make the flowers attractive to both gardeners and insect pollinators (Clapham et al. 1987).

Fortunately, the natural habitats of the species are fairly distinctive, being essentially characterised by damp, semi-shaded conditions towards the more open areas or margins of woods and hedgerows, especially on base- or lime-rich soils. Another typical habitat of the species is sheltered areas in rocky ground or on cliffs, again particularly frequent in limestone districts. The shrub is completely absent from farmland, wetland and areas of strongly acidic peaty soils.

Variation

Leaves are sometimes tinged bronze with red pigment, in the same manner as the sepals generally are semi-coloured. The leaf base sometimes clasps the stem (amplexicaul). Several named garden varieties exist. Var. 'Albury Purple' has young parts suffused dull purple; var. 'Aureum' has leaves golden yellow lined; forma variegatum D. McClintock & C. Nels. has leaves variegated pink and white (Griffiths 1994).

Flowering reproduction

Flowering takes place from June to August, the yellow flowers being solitary or in terminal, flat-topped clusters (umbellate cymes) of 2-11 blossoms. Individual flowers vary in size, usually 15-25 mm in diameter, averaging around 20 mm. The green sepals are very unequal in width and are slightly longer than the petals. They enlarge and become deflexed (bent back) when the plant fruits. In plants possessing somewhat larger flowers than average, the sepals are sometimes tinged red by the sap that gives the species its specific scientific name, 'androsaemum', meaning 'Man's Blood' (Robson 1973). The red pigment is hypericin, and it is high concentrations of this compound that gives the black colour to glands on some other Hypericum species. The filaments of the yellow stamens of H. androsaemum ± equal the petal length. Petals and stamens are both deciduous, dropping off once the fruit begins to form, while the sepals and fruit remain attached to the plant all winter (Robson 1990; Sell & Murrell 2018).

Although there appears to be little or no nectar present in flowers, abundant pollen attracts a wide variety of insect visitors including flies, butterflies, moths and bees (Fitter 1987). If insect pollination fails to occur the flowers self-fertilize. The fruit is a fleshy ovoid berry, either reddish brown or bright red becoming shiny black as it matures. Each fruit contains numerous 1 mm long seeds, estimated at between 800-900 seeds per fruit (Lang 1987).

Fermanagh occurrence

H. androsaemum is frequent and widespread throughout Fermanagh, being often recorded in 204 tetrads, 38.6% of those in the VC.

Seed dispersal

Although the black glossy fruits of Tutsan look as if they ought to attract birds, these visitors are seldom, if ever, observed on the plant in the author’s experience, or in that of other naturalists. The English Hypericum specialist, Robson (1990), admits that he has never seen birds take berries, and neither did Ridley (1930, p. 403), who discusses his observations at Kew. The 'berries' appear to often remain on the bush right through the winter and, to the human eye, they look increasingly unattractive as they shrivel with age. In the spring, they eventually split so that some of the seed may leak out, but this is hardly an effective dehiscence mechanism.

Circumstantial indirect evidence for presumed bird (or other animal) dispersal is implied by the observation that H. androsaemum seedlings and plants frequently appear, even in gardens where no plants of it have been growing (Robson 1973). In New Zealand, this species has become a serious weed subsequent to its introduction to the country around 1870. There, birds are presumed to take the berries and transport the numerous contained seed, since the plant has frequently made the 'jump' from gardens into wild wooded areas (Webb et al. 1988, p. 539).

Despite the lack of observations of birds taking the fruit in Britain & Ireland, there clearly remains a strong possibility that this is happening, meaning that bird-sown plants of garden origin are escaping into the wild, at least in open habitats near habitation.

Locally in Fermanagh, the greatest probability of bird-sown seed would be around Enniskillen. There are no other large towns or villages in the county where seed dispersal of this nature is at all likely.

Fossil history

Fossil Hypericum seed can be identified to species level, but only one seed of H. androsaemum had so far been recorded in Ireland, at Gort, from sub-stage II of the Hoxnian interglacial (a stage in Ireland renamed the Gortian), when Godwin (1975) was writing his major overview of the topic. Nevertheless, this fossil is sufficient to comfirm Tutsan as a native plant at that period. On its own, however, it does not allow us to say that it is indigenous in the current Flandrian/Littletonian interglacial. Having said this, traditionally, at least, the species is regarded as native in Ireland, and while present throughout Britain apart from the far north, it is much more common (and more likely native), only in western and southern parts of the island.

British and Irish occurrence

The boundary between native and introduced Tutsan plants is not clear and we have to accept that in the more populated areas of Britain & Ireland, Europe and N Africa, H. androsaemum is widely naturalised beyond its native range. As the overall distribution of this species is variously described as Oceanic Southern (essentially a SW European group) (Matthews 1955), Atlantic-Mediterranean (Godwin 1975), or Submediterranean-subatlantic (Preston & Hill 1997), clearly the mild aquatic climatic influences of the Atlantic and the Mediterranean are invoked and reflected in these geobotanical groupings.

The hectad distribution of H. androsaemum, as displayed in the New Atlas, is very much more western slanted in Britain than is the case in Ireland. This suggests a winter low-temperature growth limitation exists, the shrub rather obviously avoiding the colder E coast of England and Scotland, except where the occurrence possibly (or probably) represents garden escapes. The distribution (both supposed native and presumed introduced), also peters out further north in W Scotland around Ullapool (N.K.B. Robson, in: Preston et al. 2002).

European and world occurrence

H. androsaemum is native in W Europe from Belgium and Normandy southwards, becoming more local in Spain and Portugal. It stretches east through Italy, Corsica, Sardinia, Sicily, Yugoslavia and Bulgaria to Turkey and Iran, the Caucasus and Asia Minor (Lebanon-Syria). It is also reported as being native in N Africa (Algeria, Morocco and Tunisia) (Tutin et al. 1968; Clapham et al. 1987; http://www.plantsoftheworldonline.org/taxon/urn:lsid:ipni.org:names:433187-1#distribution-map (website accessed 8 February 2019).

H. androsaemum has been introduced to Maryland (USA) and to Chile. Tutsan was also introduced to New Zealand (both N & S islands), the Antipodean Isles and Tasmania in the late 19th century as a garden ornamental due to its profusion of attractive yellow flowers. Once established in New Zealand, it proved very difficult to eradicate and it can become an invasive thicket-forming weed (Webb et al. 1988). In the last 20 years, it has spread into native scrub, poorer pastures and along roadsides in several regions of New Zealand with high rainfall. It is most significantly affecting the Ruapehu District and Bay of Plenty region in North Island, where it is a difficult and expensive alien threat to the conservation of native vegetation including forest margins. Current research is looking for a suitable biological control mechanism for this weed (https://blog.invasive-species.org/2015/03/26/tackling-tutsan/ (website accessed 7 February 2019)).

Toxins

All members of the genus Hypericum contain a poisonous red, fluorescent glycoside pigment called hypericin. It is a polyphenolic compound structurally similar to fagopyrin, the photosensitising agent found in buckwheat (Fagopyrum esculentum). Hypericin has been found to have antiviral and antidepressant properties. Animals eating plants containing hypericin may develop lesions on unpigmented skin exposed to bright sunlight (ie photosensitisation occurs). This is most likely to occur on hairless areas, such as eyelids, muzzles and udders. The skin reaction can take one to two weeks to develop in sheep, cows, pigs and horses, and established lesions are slow to heal, perhaps taking months.

Lesions cause the animals to rub and scratch and open lesions can become scabbed and infected. Other symptoms reported in horses include loss of appetite, debility, staggering and even coma. Post-mortem examination of affected rabbits showed liver and kidney damage had occurred. Animals can recover, but once affected by photosensitisation, the condition more quickly reappears after further consumption of the pigment (Cooper & Johnson 1998).

Other toxins present in Hypericum include a polyphenolic flavonoid, called hyperoside, plus tannins and carotenes. However, it should be made clear that most cases of Hypericum poisoning involve H. perforatum (Perforate St John's-wort) and H. elodes (Marsh St John's-wort), rather than Tutsan (Lang 1987).

Uses

Medieval herbalists confused for some time H. androsaemum with the Agnus castus (Chaste Tree) of Pliny and transferred the latter's supposed magic virtues to it, including the reputation of warding off evil spirits and of being an 'all heal', panacea for medicinal herbalists (Allen & Hatfield 2004). This undeserved reputation is reflected in the fact that in her comprehensive book A Modern Herbal, Grieve (1931) ignores Tutsan altogether, although she does gives a little space to uses for H. perforatum (Perforate St John's-wort). In other herbal sources, there is mention only of leaves being used to make a poultice for the prevention of 'marks' on the body (bruises perhaps) (Allen & Hatfield 2004). Dried Tutsan leaves are slightly aromatic and they were, or can be, used to perfume the pages of books, mainly as a luck token. The red sap and the berries can also provide a dye. Other magical folklore uses are mentioned below.

Names

There appears to be some confusion as to the origin and derivation of the genus name 'Hypericum'. The Classical Greek form of the name is 'hypereikon' and it was used by Dioscorides (a medic in the Roman army) for an unknown plant. Differing spellings and pronunciations occur: eg Gilbert-Carter (1964) says that in England the 'i' is wrongly treated as short. Some derive the name from the Greek 'hyper', over or above, and 'ereike' a heath, possibly referring to the natural habitat of some species in the genus (Johnson & Smith 1946). Another suggestion is that the second element derives from 'eikon', meaning a picture, and thus 'Over or above a picture' might refer to the belief in the magic properties of the plant, which had the power to dispel evil spirits, and is why the Devil pierced the leaves with a needle (the translucent glands).

The flowers of some Hypericum species were placed above religious images or shrines to ward off evil at the ancient midsummer festival of Walpurgisnacht, which later became the feast of St John (24 June), when they are in flower. Hence the name 'St John's-wort' (Stearn 1972; Gledhill 1985).

The Latin specific epithet 'androsaemum' is derived from the old Greek generic name of the plant 'androsaimon', from 'aner', 'andros', man and 'haima', blood, thus translating as 'man's blood', a reference to the red sap of the plant (Gilbert-Carter 1964; Stearn 1972).

The most frequently applied English common name, 'Tutsan', is a corruption of the French name, 'Toute saine', meaning 'all wholesome' or 'all heal', a reference to the many supposed medicinal virtues of the plant. Tutsan is thus a plant of good reputation, but the species was ascribed its properties in error, having being mistaken by medieval herbalists for the plant that Pliny described as 'Agnus Castus' , 'Chaste Tree'. In reality, the latter is Vitex agnus-castus L., a tree-forming Mediterranean member of the Verbenaceae, the Vervain family, but it was not until the 17th century that herbalists in W Europe realised their earlier mistake in applying this name to H. androsaemum (Grigson 1987).

A list of 16 alternative local English common names from around Britain is supplied by Grigson (1987). These include variants of 'Tutsan', such as 'Tipsen', 'Tipsy', 'Titsum', 'Titzen', 'Touch-and-heal', 'Touch Leaf', 'Touchen Leaf' and 'Treacle Leaf'. Other names such as 'Amber', 'Sweet Amber' and 'Sweet Leaf' probably refer to the fact that heavily crushed leaves emit a slight perfume from the contained oil glands, which is like ambergris. The odour, which is sharp, aromatic and rather reminiscent of Phlox flowers in the sun, is retained and perhaps even enhanced when the leaves are dried. Dried leaves were placed inside books (including the Bible) for luck, and gave rise to names such as 'Bible Flower', 'Bible Leaf' and 'Book Leaf' (Grigson 1987).

Threats

None.

• Find out more about the format of the species accounts
• View abbreviations
• View references for all species accounts
• View a gazetteer of all the sites