Lonicera morrowii Gray (syn.: L. insularis Nakai) (Japan) – An exceptional escape from cultivation. Recorded in 2010 on a disused railway track in Brugge. A dense shrub grows at the food of planted trees (probably birdsown).
Lonicera morrowii is most similar to native L. xylosteum. It has slightly larger corollas with deeply incised upper corolla lips and usually is more densely hairy in its vegetative parts. It might have been overlooked so far.
This species and the morphologically rather distinct Lonicera tatarica are genetically very closely related and may well be conspecific (Nakaji & al. 2015).
Lonicera morrowii is a noxious environmental weed in parts of its secondary area, for instance in North America (numerous internet sources, see for instance http://www.paflora.org/Lonicera spp.pdf, http://www.invasive.org/weedcd/pdfs/wow/bush_honeysuckle.pdf). It was recently also recorded as an escape in Germany (Dickoré 2013).
Selected literature:
Dickoré B. (2013) Lonicera morrowii A. Gray verwildert in München. Ber. Bayer. Bot. Gesell. 83: 151-160.
Nakaji M., Tanaka N. & Sugawara T. (2015) A Molecular Phylogenetic Study of Lonicera L. (Caprifoliaceae) in Japan Based on Chloroplast DNA Sequence. Acta Phytotax. Geobot. 66(3): 137-151.