Planting native plant species, rather than exotic aliens from garden centres, helps promote biodiversity. As pollinators, our bees and butterflies are ‘hand in glove’ with the local ‘weeds’. There are, however, some exceptions to the botanical anti-foreigner rule.
A bush in my small garden, for example, resembled pre-lockdown Dublin Airport this summer, so many insects visited it. Yet, Buddleja davidii, ‘the butterfly bush’, hails from the far side of the world.
Peacocks, red admirals, and small tortoiseshells gorge themselves on nectar at my buddleia refuelling-stop. Then they lay their eggs on nettles. Nor are butterflies and moths the only callers to the glamorous bush.
Its scent attracts insect admirers of all shapes and sizes. Bees thrive on it. Birds like it too; warblers wrens and tits visit.
The Naturalist Field Club’s Flora of County Dublin says, rather disparagingly, that Buddleja davidii is ‘abundant as an urban weed of waste and derelict buildings’ and ‘one of the commonest weeds of the inner city’.
You find it living rough on limestone walls chimneys and ‘brown’ sites of urban dereliction. Surely it deserves to be the city’s emblematic species.
If buddleias could speak, they would have an extraordinary story to tell; theirs is a dramatic history. The Scottish surgeon William Houstoun, who died of heat-stroke in Jamaica in 1733, first brought these glamorous plants to the attention of botanists.
He asked Linneaus, the ‘father of taxonomy’, to name the genus after the clergyman-naturalist Adam Buddle. Buddle, who had died 15 years earlier, compiled an English flora which was never published.
Thanks to Houstoun, his name not only appears in botanical nomenclature, but it is also part of the vernacular, and all because of a plant he never even knew existed! ‘Buddleja’, as Linneaus spelled the name in Swedish, is retained by botanists, but has been anglicised to ‘buddleia’.
There are about 140 species in the genus. The davidii variety is called after a French Catholic missionary, Père Armand David, the first European to report it. His work was even more influential than Houstoun’s.
Sent to Beijing by his order, David travelled widely in China. A keen naturalist, he described 65 species of bird new to science and 63 terrestrial mammals, among them the giant panda and a deer which bears his name.
Père David’s deer was hunted to extinction in the wild. Captive ones were sent from China to European zoos, where they were bred successfully. Reintroduced to China, there are now about 700 living in the wild.
Buddleia has an Irish connection. Augustine Henry, who pioneered the study of Chinese plants, sent over 15,000 specimens to Europe.
In 1887, he found davidii growing near Yichang, second city of Hubei province, the capital of which is Wuhan, source of Covid-19. Henry sent davidii seeds to St Petersburg.
Another missionary botanist, Jean-Andre Soulié, sent davidii specimens back to France. His story is a tragic one. During an outbreak of xenophobia in 1905, he was one of four Catholic priests kidnapped by Tibetan lamas. The unfortunate captives were tortured over a two-week period and then murdered.
We tend to regard Buddists as gentle and non-violent. Soulié’s fate, and the Rohingya persecution in Aung San Suu Kyi’s Burma, have tarnished that reputation.