Is this Melilotus albus? I think Melilotus alba is the previous name. I don't know why I'm so confident that it's Fabaceae - the leaves look right but the flowers aren't all that convincing. Fourth photo shows fruits. At Lost Lagoon in Stanley Park in Vancouver.
Melilotus alba? T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network - Melilotus albus (White sweet clover) Melilotus albus - Wikipedia
Thanks Silver surfer and Daniel. From E-Flora BC: "Mesic to dry fields, roadsides and waste places; common in S half of BC east of the Coast-Cascade Mountains, rare to the W and N; introduced from Eurasia." Listed as Exotic.