I came upon one of these yesterday and took some shots for PF. Very un-Robinia like. But, I've found several forms of the cultivar name: Unifoliola on PF & "Hilliers Manual of Trees and Shrubs", Unifoliata label stapled on the tree & my book, "Trees of Vancouver" and Forestfarms list it as Unifolia. Anybody know what it should be called?
Both Dirr and Krüssmann list Robinia pseudoacacia 'Unifoliola'; I'd follow their lead.
Further description by Krüssman provides:
thornless; leaves mostly simple (composed of only 1, 15 cm long leaflet), often, however, with 2 or 4 small additional leaflets. Developed around 1858 in the Deniaux Nursery, Bezirk Maine-et-Loire, France.
the leaves are reduced to a single large leaflet or subtended by 1 or 2 normalized leaflets; I am almost positive that this form was used as a street tree in Paris but on a bus at 35 miles an hour it is hard to be absolutely sure; the single leaflet may be as long as 4" and 1.5" wide; it can grow 40-60' high.
I've noticed them along streets in France and Spain but have never seen one on this side of the Puddle. Did you find it there in Vancouver?
Guy S.
Yep. I was wandering Queen Elizabeth Park for PF pics. The tag was stapled to the trunk and I, honestly, hadn't heard of the cultivar. For a moment I said to myself, "Robinia - no way!" and then settled with the trunk, branches, etc that was Robinia. I think there's a few others around town and Forestfarm lists it.
