As many plant enthusiasts have observed over the past few weeks, flowering season is finally upon us. Across County Cork, the odd bright splash of spring colour is already in evidence for the sharp-eyed naturalist, as multitude species of flowering plants shrug off their wintery slumber. While a stroll in the countryside over the coming months will yield a bounty of botanical sights, the plant life of the inner city is more likely to slip under the radar of the average Corkonian. Cork has no shortage of flora – with over 570 species in the city and its environs, according to local botanist, Tony O’Mahony – but the busy atmosphere of the inner city does not always encourage us to be mindful of our surroundings, much less to stop for a moment and scrutinise a flowering plant. There is an abundance of floral life in the city, though, for those who wish to see it.
Much of the Cork city’s floral diversity may be attributed to its historic role as a port of trade. The flora of the inner-city is an eclectic mix of native Irish plants and ‘neophytes’ (non-native plant species introduced since 1500). Many of the latter were first introduced to Ireland in the 1800s via the Port of Cork, and have spread elsewhere on the island in the interim. Some were deliberately imported for their decorative value. Others were inadvertent ‘hitch-hikers’ which entered the port in the ballast water of ships, the soil of imported plants or as a contaminant in shipments of grain. The pink, white and vermillion flowers of Red Valerian (Centranthus ruber), introduced from the Mediterranean, can be seen in abundance on the quay walls of the Lee in the spring months, followed in the summer by the proud lilac spikes of the invasive Chinese Butterfly-bush (Buddleja davidii). The dainty daisy flowers of Mexican Fleabane (Erigeron karvinskianus) can be spotted bobbing in the breeze on limestone walls throughout much of the year. Another Mediterranean native, the unfortunately-named Ivy-leaved Toadflax (Cymbalaria muralis) looks perfectly at home clinging to walls throughout the city. This delightful little plant has evolved to rotate its fertilised flowerheads to face towards the wall on which it grows. Thus, these plants sow their seeds directly into the cracks and crevices of Cork’s walls. Oxford Ragwort (Senecio squalidus) – which, contrary to its name, is not native to the UK – was introduced to Ireland via the port of Cork in the early 1800s and, using railway tracks as a conduit for its airborne seeds, spread throughout the country.
The city’s geology has also played a role in supporting its floral diversity. Beneath the south side lies the fossil-rich white-grey Carboniferous Limestone of which much of the city is built. On its alkaline, lime-rich soils and limestone walls calcium-loving (or ‘calcicole’) plant species abound. Herb-robert (Geranium robertianum), Rue-leaved Saxifrage (Saxifraga tridactilytes) and introduced Bellflowers of the genus Campanula are familiar sights. Underlying the north side of the city is Devonian Old Red Sandstone. Here, ‘calcifuge’ species with a preference for acidic substrates can flourish. However, since many sandstone walls have been constructed using limestone mortar, there are alkaline hideouts for calcicoles here too. Parasitic Ivy Broomrape (Orobanche hederae), early-flowering Alexanders (Smyrnium olusatrum), Wall Pennywort (Umbilicus rupestris) and jewel-like succulent, Thick-leaved Stonecrop (Sedum dasyphyllum), may all be spotted on the north side of town. Although a fern and not a flowering plant, wiry tufts of Maidenhair Spleenwort (Asplendium trichomanes) with its characteristic black rachis, are a very common and pleasant sight on Cork city walls north and south.
We are often inclined to overlook city wildlife but Cork has an abundance of plant species which, like ourselves, are doing their best to flourish in an environment in which living space is at a premium. I have found that a familiarity with this plant life adds an extra layer of richness to the experience of city living. As this new flowering season begins, keep an eye on the old walls, quays and scrubland of Cork city and you are certain to see some of the species listed here. For those who’d like a more in-depth introduction to Cork’s flora, Tony O’Mahony’s Wildflowers of Cork City and County is an excellent resource (and available to loan through Cork City Libraries). For the newcomer to plant identification – urban or otherwise – Zoe Devlin’s Wildflowers of Ireland is the essential field guide.
by Lorraine Guerin
Doogue, D. & Krieger, C. (2010). The Wild Flowers of Ireland. Dublin: Gill & Macmillan
O’Mahony, T. (2010). Wildflowers of Cork City & County. Cork: Collins Press