Thanks, Jay.
chileflora.com is of no value - this site belongs to a predator only interested in selling seeds, including endagered species prohibited to collect.
The pictures florachilena.cl lists, are from the shrub listed on Google, but different to the one I know (and many others

).
catalogueoflife.org posts no pictures.
OK, maybe my book has a printing mistake and should read T. quinquenervia, but what to do when the shrubs are different? The only thing both have in common are spiny branches, but leaves and flowers are different. This is a picture of mine:
WAIT A MINUTE ..... how did I end up with Trevoa quinqi(e)nervis, when I am looking for TREVOA TRINERVIS - that's the entry I need!