Ipomoea purpurea (L.) Roth (syn.: Pharbitis purpurea (Roth) Voigt) (trop. Am.) – A regular but ephemeral alien. Recorded several times as a wool alien between 1936 and 1955 in the valley of river Vesdre. At present, probably exclusively associated with grain importation and primarily found in the port areas of Antwerpen and Gent (on grain dumps, unloading quays, under conveyors,…). Occasionally seen elsewhere: on dumps, in fields (introduced with manure),… Non-flowering plants are hardly distinguishable from Ipomoea hederacea. However, in Ipomoea purpurea hairs on leaves are usually ca. 0,4-0,6 mm long, while in I. hederacea hairs are 1-2 mm long (see also Grøstad & al. 2002).
Ipomoea tricolor is also very similar in appearance. It is almost glabrous, however, and has a shorter calyx up to 7 mm long. It is probably best separated on style characters: its styles are 2-fid while they are 3-fid in I. purpurea.
Selected literature
Easy G.M.S. (1983) Morning glories (Ipomoea spp). BSBI News 35: 28-29.
Grøstad T., Halvorsen R. & Elven R. (2002) Fremmede planter i Norge: praktvindlene Ipomoea L. Blyttia 60(1): 15-30.
Robbrecht E. & Jongepier J.-W. (1989) De synantrope flora van het havengebied van Gent (België, Oost-Vlaanderen), waarnemingen van 1986 tot 1988. Dumortiera 44: 1-12.
Verloove F. & Vandenberghe C. (1995) Nieuwe en interessante voederadventieven voor de Belgische en Noordfranse flora, hoofdzakelijk in 1994. Dumortiera 61-62: 23-45.