GLORIOUSLY purple American fireweed lined the canal tow path as I walked in the searing July heat to seek the shadow of Leitrim’s Iron Mountain and a cool drink at Drumshanbo’s Gunpowder gin distillery. The magnificent summer-flowering plant, which you will find across the north and west, is a metaphor for how relentless invasions have shaped and enriched modern Ireland. Since the last ice age waves of people, creatures and plants have created a tapestry which offers much more than 40 shades of green, fairy lore and fiddle music.

The population has reached seven million, according to the latest census, and has not been higher since An Gorta Mor – the Malthusian apocalypse of the great famine which is a watershed in the history of Ireland’s people. But the make-up of today’s population is very different from the era of Irish speaking peasants and English speaking landlords.

The island’s earliest known history is set down in the Book of Invasions which purports to tell how the native Tuatha Dé Danann were driven ‘sideways to the sun’ by the Celts to become the Shí – a mythical fairy host. The 20^th century writer and scholar Séan Ó Faoláin was the first to recognise the diversity of the modern Irish and how the Celts, Norse, Normans, English and Scots all played an important part in the Hibernian story.

Today you can add a whole range of other races to the list. Membership of the European Union gave our continental neighbours the right to live and work here and many chose to settle and raise families because of the quality of the life they found. Among them are people from England including film director David Puttnam who has taken Irish citizenship after 25 years living in county Cork and in disgust at the ‘pig ignorance’ about Ireland he found in Britain’s House of Lords.

The nation’s reputation for charity saw many who fled persecution, prejudice and poverty come to our shores. The hospitality trade is dependent upon eastern Europeans for labour and the food processing industry is dependent upon ‘non-nationals’ from poor places in southern Europe who are trying to better themselves in tough jobs with low wages. There is an electronics company in Enniskillen where the majority of the workforce is from Lithuania. A director told me, “I’ll take all of them I can get and worry they might leave because of Brexit. They are first in line when overtime is needed and never phone in sick because they have a hangover.”

I stopped to ask for directions in Cookstown county Tyrone, a place with a bacon factory, and approached several people before I could find an English speaker. Black faces are a common sight even in small rural towns. I bought a bodhrán in Roundstown county Galway from Malachy Kearns and enjoyed a long chat about life in Ireland with Gifty his charming Ghanaian wife. Love crosses boundaries of race and religion. I asked Michael, a Dutchman who is a guide at the Ballynahinch salmon fishery, why he settled in Connemara. He said: “The women.”

Hong Kong people have been settling in Northern Ireland since the 1960s and there is hardly a high street across the island that does not have a Chinese takeaway and a Turkish barber shop. The Polish have settled in such numbers that many places now have shops that specialise in selling them familiar foods from home. The latest wave to arrive is Ukrainian, people fleeing war in their own country. It is inevitable some of them will settle.

Galway sheep and Kerry cattle are the only native species. Scottish blackface sheep were imported in the middle ages because they produce a better crop of wool and Friesian cattle are everywhere because they deliver high yields of milk. Ireland’s only native fishes are salmon, trout and eels but the rivers and lakes are teeming with pike, roach, bream and perch which were probably introduced in the Norman period as a source of food.

The fields and hedgerows are a riot of colour in spring and summer and American fireweed is not the only alien species which decorates the landscape. Many of these plants are from other parts of the world and have escaped from planned gardens. The blood red fuchsia, from Chile, and bright orange monbretia of southern Africa have earned a place on picture postcards of the west. The hardy buddleja is everywhere, it can even take root in the clefts of urban buildings, and is a welcome source of nectar for the butterfly population.

Like some people, a few plants and animals are less welcome than others. The rhododendron, which has origins in central Europe, has become a pest in many areas because it grows thick on peaty upland soils. The Indian balsam has a pretty pink flower but is the bane of river keepers because it spread so rapidly along watercourses. Japanese knotweed is so vigorous it can undermine buildings and roads in towns and cities. Like the poisonous giant hogweed it requires expert handling to be removed.

The American grey squirrel is a threat to the native red. Mink, which have escaped from fur farms, are ruthless killers of all kinds of defenceless creature. Anglers in the north are increasingly catching pink Pacific salmon which have crept around the Arctic Circle and must restrict the movement of boats to prevent the spread of Asian zebra mussels. Valuable work is underway to stop the voracious American crayfish reaching Irish waters where it will threaten the native stock but it is too late to prevent the introduction of the New Zealand flatworm which preys upon native earthworms.

Attitudes to aliens of all kinds are hardening but Ireland’s book of invasions is not yet closed. Climate change and human cruelty will bring more exotic visitors to our shores whether they find a welcome or not. In the words of Ulster’s Planter poet John Hewitt – the soil and the atmosphere will make them Irish.

Mneill1@ymail.com