On the
Mediterranean Climate Gardening Facebook group (which is used by many MGS members, and which I help to moderate), one of our members has asked for ID of this plant, which she says "is growing happily on the Algarve in Portugal and we think it is from California. After several years it is now a tall shrubby tree of about 5m. Lovely perfume, delicate and reminds me a bit of Sambucus (elder flowers)".
Familiar to anyone?