This record just got brought to my attention. It looks atypical for S.recta so I Keyed it.
Apices of leaflets obtuse, retuse or emarginate, if acute then not long-tapering (10-11 other species) Apices of leaflets narrow and long-tapering (S.recta)
The leaf apices are obtuse in this case, not long and tapering. That rules out S.recta. I suspect these plants are S.galegifolia, but given it's a planted specimen i think genus is fine for the ID