3. Erodium malacoides (L.) L’Hérit. (Medit., SW-As.) – A surprisingly rare and ephemeral alien. First recorded as a wool alien in the valley of river Vesdre in Ensival in 1902. Apparently slightly increasing in the past decades. Found on a dump in Antwerpen in 1975, possibly from birdseed. Also seen on a demolition site of a former horse artillary in Gent in 1994 (from a long-buried seed bank, obviously a hay or grain alien). Erodium malacoides is also regularly introduced as a weed in olive containers in plant nurseries (Hoste & al. 2009).
Erodium malacoides is a very variable species and perhaps better treated as an aggregate species (Euro+Med PlantBase). A related species with more deeply lobed leaves is sometimes accepted as a distinct species, Erodium neuradifolium Delile (beautifully illustrated in Slavík 1996b, 1997). A non-flowering plant, collected in 2003 on worked-up soil at road works in Antwerpen, possibly belongs to that species.
Selected literature:
Bruggeman C.J.M. (1964) Overzicht der in Nederland gevonden inheemse en adventieve Erodium-soorten. Gorteria 2(5): 49-55.
Hoste I., Verloove F., Nagels C., Andriessen L. & Lambinon J. (2009) De adventievenflora van in België ingevoerde mediterrane containerplanten. Dumortiera 97: 1-16.
Slavík B. (1996b) Erodium neuradifolium – a new species in the flora of the Czech Republic. Preslia 68: 173-176.
Slavík B. (1997) Geraniaceae. In: Slavík B. (ed.), Kvĕtena České Republiky, vol. 5. Academia, Praha: 191-229.