Ipomoea x leucantha Jacq. (syn.: I. lacunosa f. purpurea Fernald; = I. lacunosa x I. trichocarpa S. Elliott) (SE-USA) – A very rare and ephemeral grain or oilseed alien. Recorded in 1997 near a grain mill in the port of Gent. Subsequently grown from sludge, extracted from docks in the port of Antwerpen.
Up to present these records were ascribed to pinkish-coloured forms of Ipomoea lacunosa or even I. trichocarpa (see for instance Clement & Foster 1994). However, they are perfectly intermediate between these species: capsules are smaller than in I. lacunosa and corollas are smaller than in I. trichocarpa. These taxa belong to the Ipomoea batatas complex (Austin 1978) in which introgression frequently occurs. This has considerably blurred the species boundaries and “pure” Ipomoea trichocarpa might no longer exist. A recent morphometric analysis demonstrated that Ipomoea xleucantha is the most variable weed in this species complex and largely confused with related taxa (Bryson & al. 2008).
Outside its native range, Ipomoea xleucantha has become a more or less widespread weed and now occurs in parts of Central and South America, as well as in parts of Asia. It spreads without its putative parents. It is recently becoming naturalised in parts of southern Europe as well (for instance in Spain; see Verloove & Sánchez Gullón 2008).
Selected literature
Abel W.E. & Austin D.F. (1973) Natural hybridization in Ipomoea (Convolvulaceae). Amer. J. Bot. 60: 33-34.
Austin D.F. (1978) The Ipomoea batatas complex – I. Taxonomy. Bull. Torrey Bot. Club 105: 114-129.
Austin D.F. (2006) Noteworthy distributions and additions in southwestern Convolvulaceae. Canotia 2(3): 79-106. [available online at:
http://www.canotia.org/volumes/CANOTIA_2006_Vol2_3_Austin.pdf]
Bryson C.T., Reddy K.N. & Burke I.C. (2008) Morphological comparison of morningglory (Ipomoea and Jacquemontia spp.) populations from the Southeastern United States. Weed Science 56: 692-698.
Chen P.-H. & Sheng-Zehn Y. (2017) Ipomoea leucantha Jacq. (Convolvulaceae), a Newly Naturalized Plant in Taiwan. 國立臺灣博物館學刊 70(1): 1-8. [available online at: https://www.researchgate.net/publication/330482453_Ipomoea_leucantha_Jac...
Clement E.J. & Foster M.C. (1994) Alien plants of the British Isles. BSBI, London: XVIII + 590 p.
Verloove F. & Sánchez Gullón E. (2008) New records of interesting xenophytes in the Iberian Peninsula. Acta Bot. Malacitana 33: 147-167.