Urban nature: at home in the city

There are plants that thrive in the (sub)urban environment and can be seen growing in unexpected places. Some of these plants are adaptable species that exploit favourable growing conditions. Sometimes even so much so that they are considered a weed. Other plants can be found happily growing in the urban environment whilst botanists know them to be specialists of a particular growing environment. Some of these plant can be -locally-abundant in the (sub)urban environment whilst very rare in the wild. Urban Areas are now also included in the list of flora districts or habitats of the Low Countries.

Rosebay willowherb (Chamerion angustifolium) is known in America as Fireweed as it's often one of the first plants to reappear after a forest fire. The large flowers are followed by pods that produce large amounts of tiny plumed seeds that drift on the wind and float on water. It has a preference for damp to wet soil and is associated with disturbed ground. Here (shown left) it grows happily in a cracked concrete driveway. Throatwort, or the Nettle-leaved bellflower (Campanula trachelium) is a beautiful plant of woodland edges that was once abundant in coppiced woods. As that practice has been mostly abandoned the plant has become rare in the wild. Sometimes it can be found in a suburban setting in humus rich corners in cool shade. A close relative, the Creeping bellflower (Campanula rapunculoides), can be found growing along the side of pavements against north-facing facades. This perennial, that naturally thrives in the dry shade of woodlands and hedgerows, spreads by underground runners and can become a weed in gardens. It is a protected and rare species in the Low Countries, but has become established in several cities.

Typical woodland species can become very abundant in urban parks, graveyards and gardens. Hedge woundwort (Stachys sylvatica) grows naturally in hedgerows and in the dappled shade of the woodland edge. It can become abundant in parks on rich soil (shown left). Another indicator of rich soils is Ground-ivy (Glechoma hederacea), an evergreen ground cover that isn't related to Ivy but  rather to Woundwort and Sage. It thrives in moist shady areas, and will invade the sunny turf of a lawn given sufficient moisture. Enchanters' nightshade (Circaea lutetiana) is another species normally found in moist woodland on rich soils. As it tolerates deep shade it is often found in 19th century parks that have become overgrown and as a result densely shaded.