A younger plant that was found while walking along SE Salmon Way. The plant was ~1m east of the road (coordinates: 45.5135270531, -122.5979287285; accuracy ±10m) on a vegetated, lowly sloped hillside. No other plants of this species were seen in the vicinity but my search was very general and in post-sunset lighting conditions.
ID: "Can be distinguished from Scotch broom by its leaves always in threes (some Scotch broom leaves are single); younger stems are green, ridged and very leafy; and leaves and young stems covered with silvery hairs."