Cookstown Wildlife Trust Aliens
© R.Irvine2011
founded February 1950
Some naturalized plants of Mid-Ulster . Some plants growing wild in Ireland only arrived within the last 100 years. our flora has been flooded by imports from North America,The Himalayas, Mediterranean countries, Eastern Europe and as far away as New Zealand .  The word “Alien” is used to describe them, a word better used for the most invasive. Even the beech is not native to Ireland.  Some have become so well established that eradication programmes are necessary . Himalayan Balsam,with pretty pink, white and red flowers,allows little else to grow underneath its broad leaves. Giant Hogweed, with ulcer causing sap grows taller and requires more legroom than any native herb, and Laurel allows no competition. In the late 19th and early 20th Centuries plants were brought in by estate owners either as curiosities or embellishments for gardens. Others may have been carried from docks and along railways . The late 20th Century saw an explosion in transport.  Air travel,continental lorries, cars returning from holidays abroad, and plant imports to nurseries are means by which foreign plants arrived. Recent warm years have allowed more species (which might not have previously survived) to become established. The Ballinderry flows to the south side of Cookstown . Upstream, rivers pass through old estates such as Tullylagan , Loughry and Killymoon. Many unusual naturalised plants seen downstream of these estates were brought by the well-travelled families who once lived there. The local Railway Yard has Oxford Ragwort, brought by trains more than 60 years ago, and still persisting in neglected corners. Cookstown area has the largest population of Few Flowered Leek in N. I. It often grows on dumped soil and is frequent along the river. Drum Manor hosts a Mediterranean prostrate plant known as “Corsican Mint” around the old house.  This has persisted for possibly more than 100 years.Why was it brought? Recently many gravel paths in forests have gained a scattering of Peri Peri Burr from New Zealand, (I first saw this plant on sand-hills in Northumberland opposite Holy Island in the early 1980’s). Removing seed-head burrs from clothes is a major operation. The descriptions and photographs below show some of the local plants with origins far away from here. 
Few Flowered Leek
Few Flowered Leek (Allium paradoxum). From Eastern Europe (Iran and Caucasus region) Ballinderry river banks and occasionally on waste areas around Cookstown. Allium paradoxum var.paradoxum, in flower from April to May produces mainly bulbils instead of flowers, the seeds ripen in June. This form is naturalized in Britain and can spread quite invasively .The plant prefers light (sandy) soils, semi-shade and moist soil. Leaves and bulbs can be eaten, either raw or cooked.
Click pictures to enlarge.
Giant Hogweed
Giant Hogweed (Heracleum mantegazzianum) The most invasive and dangerous alien in Britain, from the Caucasus. Like many invasive alien plants, introduced in the 1800s for architectural beauty. From estates it escaped into water courses, growing into dense colonies difficult to eliminate. The sap produces severe skin burns in sunlight and can cause chronic effects. A member of the carrot family and a  relative of common hogweed, recognisable by a long ribbed stalk, green lobed leaves and a flat umbrella-shaped head. G.H. flourishes in wet areas, often riverbanks . It flowers in mid-summer and seeds appear in late July. Seeds remain active in the soil for several years. The plant's dense foliage prevents light reaching the ground beneath. Other vegetation is killed off leading to rapid soil erosion. Laws prohibiting its growth and spread are active in many countries.
Mimulus guttatus
Monkey-flower (Mimulus guttatus) where it grows along banks of streams and in damp flushes. From Western N. America Frequent on banks and rocky ledges of the Ballinderry river where it has found an ideal home. Some sources said that it can be invasive, however it seems to have found a niche on several of our rivers and appears to hold its own without being invasive  .     
Peri peri burr
Pirri Pirri Burr (Acaena ovalifolia) A native of New Zealand, Australia and South America. Possibly came with sheep. Forest tracks-Davagh, Banagher  A low-growing evergreen perennial which spreads by rooting stems. A nuisance on sand dunes and in forestry plantations.  In summer, spherical clusters of small cream flowers appear on short stems. They turn brown with spiny hooks which attach persistently to animal fur.
Yellow Archangel
Yellow Archangel(Lamiastrum galeobdolon) Found wild in England but only naturalised here. Naturalised in Loughry estate, spreads vegetatively and over large areas. Most garden and "wild" plants in Northern Ireland belong to subsp. argentatum  with conspicuous white patches on the leaves.
Himalyan Balsam
Himalayn Balsam(Impatiens grandulifera) An annual related to Busy-lizzies, introduced in 1839 to Kew Gardens. It escaped and became  naturalised. An invasive plant, and should be removed when found. Seeds travel along waterways and germinate in early spring even under water. Grows 2 metres tall, on river banks, and damp areas. Thick growth smothers other plants, leaving river banks bare and liable to winter erosion. Flowers-policeman's helmets- vary from pale pink to purple, readily attracting pollinating insects and reducing pollination of native plants. One plant sets about 800 seeds. Seed capsules react to slight disturbance, curling and twisting explosively, projecting seeds 7 metres away.
Tellima grandiflora
Fringe Cups(Tellima grandiflora) From Pacific States of N.America, from Alaska-Oregon Banks of Ballinderry at Loughry and further downstream. Fringe Cups, an upright perennial with hairy leaves and tall spikes of fringed bell-shaped green-white flowers in early summer. Flowers have striking sun lotion smell. Usually in shade, it produces plenty of seed and has spread down river from possibly Tullylagan.
New Zealand Willowherb
New Zealand Willowherb (Epilobium brunnescens) From New Zealand noted first between1905 and 1910. Drum Manor, Lough Fea,Slieve Gallion, Banagher etc. Another low-growing perennial with many small paired rounded leaves on creeping stems. Ubiquitous on damp gravelly mountain paths and rock crevices.  The pinkish-white flowers stick up on seed pods like other willow-herbs. The seed capsules split and curl releasing seeds dispersed by wind.
Oxford ragwort (Senecio squalidus) A hybrid between two Senecio species native to Mount Etna in Sicily. It was introduced into the UK  around 1690 by escaping from Oxford  Botanic Garden and became plentiful on almost every wall in Oxford by 1800.    Frequent in old railway  yards in Cookstown. Oxford ragwort found a new home on railway lines around Oxford and has spread to most parts of the UK via the transport system.  During its spread across the British Isles, Oxford ragwort has hybridized with other native Ragwort species, particularly groundsel (Senecio vulgaris) to form new hybrids,
Oxford Ragwort Cherry Laurel
Cherry Laurel(Prunus laurocerasus) Rapid growth, evergreen habit and tolerance of drought and shade allow it to out-compete and kill off native plant species. It is spread by birds, through seeds in their droppings. Once established, eradication is a major job. A large shrub often forming huge thickets in planted woodland. Native to SW Asia (around the Black Sea etc.) and the eastern Balkans; introduced to Ireland and now a nuisance in many places. Leaves are thick and laurel-like, and poisonous due to hydrogen cyanide. White flowers are produced on upright spikes followed in autumn by black cherry- like fruits which should not be eaten.