trifoliate orange: small fast-growing spiny deciduous Chinese orange tree bearing sweetly scented flowers and decorative but inedible fruit: used as a stock in grafting and for hedges
tree: a tall perennial woody plant having a main trunk and branches forming a distinct elevated crown; includes both gymnosperms and angiosperms
heliophila: any of various South African herbs and subshrubs cultivated for long showy racemes of bright blue flowers with white eyes