Acanthomintha lanceolataâSanta Clara thorn mint. Included in the CNPS Inventory of Rare and Endangered Plants on list 4.2 (limited distribution). An annual thorn mint that grows in the Diablo Range from about Cedar Mountain in Alameda County to Southeastern Monterey County. Nearly all populations are found on a serpentine substrate. Note the thorns that give the genus its common name. Photographed at Regional Parks Botanic Garden located in Tilden Regional Park near Berkeley, CA.