Oleander

Nerium oleander

Family: Apocynaceae

Oleander

Oleander

This is most commonly seen on highways in this part of the world where it is planted in the median strip, e.g., Highway I80 between Davis and Sacramento, or on the center divide of Freeport Boulevard and many other streets. It flowers  profusely in the hottest part of summer and needs very little water.  It is also highly poisonous!

Resources

Wikipedia