P. vialii is an attractive species easily identified by its spikes of flowers with red calyces. It comes from N and NW Yunnan and SW Sichuan and grows in wet meadows. Considered rare in the wild, it is often cultivated in gardens where it appears above ground late in the season. Hybrids with P. flaccida are known in cultivation as shown in the last image. Synonym P. littoniana can not be distinguished by any characters from P. vialii.