Parrotia
Sponsor
Kindly sponsored by
Lucy Garton
Credits
Owen Johnson (2024)
Recommended citation
Johnson, O. (2024), 'Parrotia' from the website Trees and Shrubs Online (treesandshrubsonline.
Family
- Hamamelidaceae
Common Names
- Ironwoods
- Parrot Trees
Synonyms
- Shaniodendron M.B. Deng, H.T. Wei & X.Q. Wang
Two species of deciduous trees or large shrubs, suckering and also layering. Bark whitish-grey to dark brown, ultimately flaking or peeling in flakes or rolls to show the brighter and paler underbark. Twigs grey-brown, pubescent when young; buds brownish, ovate, with pubescent protective scales. Leaves alternate, simple, entire or with dentate margins, with stellate pubescence on both sides at least when young; petioles short; stipules large but soon shed. Inflorescence a terminal or axillary capitate spike with 3–7 flowers surrounded by brown protective bracts, opening in late winter to early spring. Flowers male or hermaphrodite, composed of 7–10 spirally arranged, irregularly sized sepals and the reproductive parts inserted onto a shallow floral cup or receptacle; petals absent. Stamens 5–15, with conspicuous rufous to crimson anthers; ovary semi-inferior with long styles. Fruit a sessile, woody nut-like capsule with one seed in each locule, densely stellate-pubescent outside. (Zhang, Zhang & Endress 2003; Andrews 2008).
Parrotia is an example of a Tertiary relic genus, of which just two representatives survive in small and widely separated forest refuges – one in the mountains south-west of the Caspian Sea in Iran and Azerbaijan, the other in central China. The genus seems to have diverged from its nearer allies during the Miocene epoch; these include Hamamelis, the witch hazels, whose flowers differ in bearing petals and being insect pollinated. A fossil Parrotia flower was discovered in 2023 in 15 million-year-old sediments in Fujian Province, south China, and was named P. zhiyanii after the Chinese paleobotanist Professor Zhou Zhiyan (Hang 2023). Like Hamamelis and its allies, Parrotia displays a singular method of seed dispersal: as the seed capsule dries, the exterior wall shrinks until the seed is suddenly and forcefully ejected (Douglas & Sjöman 2021).
The habitat in which Parrotia zhiyanii grew was tropical rainforest, but the genus’ survival through more recent Ice Age-related climate change has empowered both the surviving species to thrive when grown in conditions much colder than they currently experience in the wild. They are also attractive plants year-round: the older bark flakes or peels to reveal patches of the underbark which can be amber, orange, white or even greenish; the flowers with their lipstick-red stamens, while hardly spectacular, open very early in spring; the leaves can flush with bronze to purple tints and through summer remain a bright, fresh green, often with coloured young leaves at the branch-tips; in autumn these leaves can turn a rich variety of yellow, red and even purple colours. Of the two species, the west Asian P. persica has been cultivated in western Europe for the best part of two centuries and is finally becoming a little more popular here as a garden tree; P. subaequalis has only been grown outside China since the very first years of the 21st century, but its endangered status in the wild has given it some degree of prominence among the many ornamental Chinese plants of recent introduction. The differences between the two species are particularly subtle and are discussed here under the entry for P. subaequalis.
