Species Factsheets
Lactuca hirsuta
Downy Lettuce
State Status: N
PBS Status: Tenatively Undetermined (TU)
Federal Status:
Global Rank: G5?
rank interpretation
State Rank: S3
Did You Know?
After only a short period of time the flowerheads of this species get replaced by small, black achenes that have tufts of white hair.
Description
Downy lettuce (Lactuca hirsuta) is an annual or biennial herb with milky sap. The slightly to densely hairy stem can reach 2.5m in height. The leaves are arranged alternately on the stem and variable in shape and length, but tend to have toothed, pinnate lobes. The flowers are individually tiny and are grouped in yellow flower heads that are 15-22mm long at maturity. The individual fruits have a slender “beak” at the top, somewhat similar to dandelions. The flower heads and fruits of downy lettuce are slightly larger than the very similar and much more common species of wild lettuce, Lactuca canadensis.
Rank Justification
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.
PABS
The PA Biological Survey considers downy lettuce to be a species of special concern, based on the relatively few occurrences that have been confirmed in the state. It has been assigned a rarity status of Undetermined, meaning that more information is needed before a more definitive rarity status can be designated.
Habitat
The species grows in open woods, clearings, thickets, powerline and pipeline rights-of-way, and ridgetops.
Survey Dates
Flowers August - September
Distribution
In Pennsylvania, it has been found scattered throughout the state.
Management
More field surveys are needed to determine the range, abundance, and ecological requirements of downy lettuce before a more definitive conservation status, if any, can be assigned. Based on current data, it appears to be a short-lived, early successional species that may have a very limited viability at a given occurrence, even under optimal conditions.
Conservation Status Map
NatureServe. 2017. NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia. Available https://explorer.natureserve.org.
https://eol.org/pages/467163/overview
- NatureServe. 2018. NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia. Available at https://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.
