Ceanothus has a common name of California lilac. Jacaranda trees have purple flowers. I believe they are fragrant.

If the same as in the OP photo, it was correctly identified as Duranta erecta and very likely the cultivar 'Sapphire Showers'. It is subtropical in origin and will not survive a New England winter in the ground. Rated to only zone 10 but can take a light frost.

I love the picture of the native Wisteria! I really love the invasive Wisteria too, but would never plant it. It's pretty but evil. There is a large wisteria vine on a dogwood across the street from me. When we moved in 8 yrs ago it was beautiful in bloom because they bloomed at the same time and there was all the white and purple from the two flowers. Needless to say there is no longer any white. I am not sure if there is any life to the dogwood now or if it is just a support for the vine. Now the wisteria is climbing to adjacent trees and if it were my property I would be very concerned. It's still beautiful. Looks like a wisteria tree. It also sends little baby wisterias over to my yard which I militantly pull out. -Ais.

I am not familiar with the Algarve area however, I have seen a few specimens of T. riparia within the Sydney ( Aus.) metropolitan area. Color is somewhat variable in the flowers with a broad variation going from whites, pinks and thru to almost purple. The leaves and other main identifying characterists typically show less variation. Hard to say about color enhancements floral, I guess some jpeg files show the usual automated processing performed by the camera which sometimes cause images to appear over-saturated. If we can see a better photo it might help to reach a positive ID.