What is the fine-grained topic of the following text: Poncirus trifoliata growing tree or shrub of the genus Poncirus also known as Trifoliate orange, Poncirus trifoliata grow as perennial deciduous used more as ornamental thorny plant, it can grow in tropical, subtropical, mediterranean or temperate climate and growing in hardiness zone 6+. Only return the topic.
Poncirus trifoliata (Trifoliate orange) growth and characteristics.