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The new site offers several benefits over the existing website, including real coordinate mapping, giving a clearer view of the density of documentation as well as more precision about plant distributions and their link to landforms. We will also have the ability to update species pages more regularly, both in terms of new collections and as more existing Michigan specimens are georeferenced. In addition, we have a better photo display, and offer indented keys.

Dioscorea polystachya Turcz.
Common Name: CHINESE YAM
Coefficient of Conservatism: *
Coefficient of Wetness: 5
Wetness Index: UPL
Physiognomy: Ad P-Vine

Dioscorea polystachya  stand A. A. Reznicek stand

A species of eastern Asia, occasionally cultivated for the edible tubers and rarely escaping to thickets and disturbed areas. First collected in 2015 in Ottawa Co. by W. S. Martinus.

This rapidly growing vine is very distinctive, producing irregular, brownish aerial tubers ("bulbils") in the upper leaf axils, which are the primary means of dispersal. It is cultivated, both for food and as an ornamental for its distinctive appearance. It is invasive south of Michigan, spreading into natural areas, and should be carefully watched.

Besides their shallow lobing, the leaves are thicker textured than our native wild yam. Lower leaves are typically alternate, but upper leaves, especially those bearing the distinctive aerial tubers, are generally opposite.


Ottawa County


MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. January 30, 2023.