Article from Bean's Trees and Shrubs Hardy in the British Isles
Recommended citation
'Pertya' from the website Trees and Shrubs Online (treesandshrubsonline.
A genus of a few species of herbs and shrubs ranging from India to Japan. Flower-heads solitary or arranged in racemes or panicles; florets all tubular, the corollas deeply divided into five segments. Involucres with numerous imbricate membranous or leathery bracts. Named in honour of J. A. Maximilian Perty, Swiss naturalist, 1804–84.