State Status: Pennsylvania Rare (PR)
PBS Status: Pennsylvania Rare (PR)
Global Rank: G5
State Rank: S3
Did You Know?
This species was a main grain for many Native American tribes in northern climates - so much so that it was even fought over for.
Annual wildrice (Zizania aquatica) has very tall, hairless stems that may grow to 3m in height. The leaf blades are alternately arranged, linear to lanceshaped, pointed at the tip, not toothed on the margin, parallel-veined, and often well over 30cm in length and up to 5cm in width. The flowers are grouped in a large branched cluster at the top of the stem, with the female flowers located on the ascending upper branches and the male flowers located on the spreading or drooping lower branches. The small bracts subtending each female flower have an elongate bristle-like projection, or awn, up to 6cm in length.
Vulnerable in the nation or state due to a restricted range, relatively few populations (often 80 or fewer), recent and widespread declines, or other factors making it vulnerable to extirpation.
Annual wildrice grows in marshes, particularly intertidal marshes along the Delaware River in southeastern Pennsylvania, as well as on shorelines and in shallow water elsewhere.
Flowers late May - early September
In Pennsylvania, it has been documented historically in several southeastern counties, as well as the counties of Erie and Huntingdon.
Some populations of annual wildrice have threats from exotic species, dredging and filling, and water pollution.
The species appears to have an ample number of populations and to be adaptable enough so as not to be endangered or threatened with extirpation, yet has a very localized distribution in the state.
Conservation Status Map
NatureServe. 2017. NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia. Available http://explorer.natureserve.org.
- NatureServe. 2018. NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia. Available at http://www.natureserve.org/explorer
- Pennsylvania Natural Heritage Program. 2018.
- Rhoads, A.F. and W.M. Klein, Jr. 1993. The Vascular Flora of Pennsylvania. American Philosophical Society, Philadelphia, Pennsylvania. Rhoads, A.F. and T.A. Block.
- 2007. The Plants of Pennsylvania: An Illustrated Manual. 2nd edition. University of Pennsylvania Press, Philadelphia, Pennsylvania.