Sourwood (USA, 8 / 8 jars)
Appalachian ridgetops, late June through August.
Range: Confined to Oxydendrum arboreum — a tree that only grows on well-drained Appalachian ridges at 300–1,500 m elevation, from North Georgia to West Virginia.
Bloom: Bloom window: 3–4 weeks, mid-July on average.
Why it can't move: Sourwood trees do not coppice; they are slow-growing understory specialists in oak-hickory forest. Commercial monoculture is not possible and beekeepers truck hives to mountain orchards. Every "sourwood" jar in the catalog is from a US beekeeper because no other continent has the tree in commercial density.
Refs: Horn, T. "Bees in America: how the honey bee shaped a nation." Uni. Press of Kentucky. USDA NRCS plant profile for Oxydendrum arboreum.