Grewia occidentalis

The crossberry is an interesting shrub or small tree native from Southern-Africa, with showy purple flowers in summer. Fruits are small and sweet, four-lobed (hence the common name crossberry). They ripen variably in yellow, orange or red. It is easy and adaptable, both frost- and drought-hardy.

Pictures from wikimedia commons:
"Starr 980529-4195 Grewia occidentalis" by Forest & Kim Starr. Licensed under CC BY 3.0 via Commons - https://commons.wikimedia.org/wiki/File:Starr_980529-4195_Grewia_occidentalis.jpg#/media/File:Starr_980529-4195_Grewia_occidentalis.jpg
By Paul venter - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=34395306