Asplenium obovatum Viv. subsp. lanceolatum (Fiori) P.Silva (Lancetvormige streepvaren): niet zomaar een nieuwe muurvaren

Asplenium obovatum Viv. subsp. lanceolatum (Fiori) P. Silva was discovered on an Amsterdam quay wall with a fern-rich wall vegetation in 2015, the first record of this subspecies in the Netherlands. Asplenium obovatum subsp. lanceolatum is a Mediterranean-Atlantic subspecies with its core distribution in southwestern Europe, extending from Spain to Brittany and southern England. Hence, the occurrence of this subspecies in the Netherlands fits well with its natural distribution, but climate change may have played a role as well. The Dutch climate is becoming more Mediterranean, which favours northwards migration of Mediterranean-Atlantic plant species. Nevertheless, since there is a significant decrease in other peripheral locations, the new occurrence of A. obovatum subsp. lanceolatum in the Netherlands is remarkable.