How did I take this photograph? Very carefully. This Japanese honey locust is located near a rubbish bin, an attractant to the local population of yellow-jacket wasps. Since the bin is sealed, the wasps instead congregate on this tree – one landed on these pods a few seconds after taking this shot. Oddly, most of these 20cm (8in) long pods had been (or were being) chewed down by the wasps, particularly those pods in less exposed areas.
This is one of those plants for which the scientific name is being settled upon. Originally received by UBC Botanical Garden as (and posted to BPotD as) the variety koraiensis, this was thought to be a Korean morphological variety of the species identified as distinct from the rest of the species by Nakai (though it also grows in China and Japan). Authoritative taxonomic databases did not reflect Nakai’s interpretation, instead placing it strictly as the species Gleditsia japonica. We updated the name of this plant in our collections to match the authoritative databases in 2007.
In Phylogenetic relationships in Gleditsia (Leguminosae) based on ITS sequences (Am. J. Bot. 2003;90:310-320), Schnabel et al. were not able to provide a definitive answer as to whether the variety koraiensis should indeed be recognized taxonomically, to wit:
In addition, our two molecular data sets show different relationships among the G. japonica accessions. The cpDNA data suggest that the South Korean and Japanese accessions cluster separately from the Chinese accessions. In contrast, all the analyses of ITS data alone and the ML analysis of combined data place the South Korean accessions in one clade and the Japanese and Chinese accessions in a second clade. More extensive sampling of G. japonica, especially in China, will be necessary to determine whether any of the subspecific designations of G. japonica are phylogenetically justified and to clarify the taxonomic complexity of this group.
It needs to be noted that clarifying the taxonomic complexity at this resolution was not the main goal of their work, as they were looking at Gleditsia more broadly. The researchers did suggest that more data was needed; this is achievable, as the species is in no way threatened.
Nature resource link: I linked to it five months ago, but it’s worth mentioning again since there are so many new readers of BPotD–“Beauty and the Botanist“, an essay by the late Dr. Stan Rowe. If you’ve ever wondered about BPotD’s tagline, “In science, beauty. In beauty, science. Daily”, this is the essay that serves as the inspiration.