State Status: Pennsylvania Rare (PR)
PBS Status: Pennsylvania Rare (PR)
Global Rank: G4
State Rank: S3
Did You Know?
Naturally this species grows in rivers with both fresh and brackish waters, but it can also be used in aquariums.
Subulate arrowhead (Sagittaria subulata) is a small perennial herb only about 20cm in height that forms small mats due to its horizontallyspreading stems. The leaves are linear to strap-shaped, up to 7.5cm in length and four milimeters in width, somewhat spongy, and do not have an expanded leaf blade at the tip. The flowers, appearing from June to September, have three white petals that are only a few millimeters in length. The individual flowers are grouped in a whorl-like cluster. The sepals of each flower are persistent, and are spreading or bent down beneath the fruiting heads, which consist of a group of flattened, one-seeded fruits that are one or 2mm 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.
The PA Biological Survey (PABS) has assigned subulate arrowhead a rarity status of Rare.
Subulate arrowhead grows in intertidal marshes, mudflats, and river shores. The intertidal populations are subjected to daily cycles of exposure and inundation.
Flowers June - early September
In Pennsylvania, it has been documented recently only in a few southeastern counties along the Delaware River.
The populations of Subulate Arrowhead have threats from exotic species, dredging and filling, and water pollution.
The species appears to be successful enough in maintaining its populations so as not to be endangered or threatened with extirpation, yet has a very limited range in the state and a very specialized habitat.
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.