State Status: Pennsylvania Threatened (PT)
PBS Status: Pennsylvania Endangered (PE)
Global Rank: G5
State Rank: S1
Did You Know?
The name for this species from the Greek word speira, which means "wreath"; this references the flower clusters that can be found on the shrubs.
Dwarf spiraea (Spiraea betulifolia) is a perennial shrub that is a member of the rose family; it is sometimes referred to as Spiraea corymbosa. It grows to about .5-1 meter in height and is capable of forming dense clumps of clones in areas with reduced tree canopy.
Critically imperiled in the nation or state because of extreme rarity (often 5 or fewer occurrences) or because of some factor(s) such as very steep declines making it especially vulnerable to extirpation from the state.
Dwarf spiraea occurs on dry upland sites, wooded slopes, and steep shale hillsides in the Ridge and Valley region of Pennsylvania.
Current populations exist in Fulton County; historically however, there are records for Bedford and Franklin Counties as well.
The northern extent of dwarf spiraea's range occurs only slightly into Pennsylvania, exclusively in the Ridge and Valley region of the state. Dwarf spiraea is a plant of special concern due to its specific habitat requirements. This species can reproduce asexually via cloning; this however limits the genetic diversity of the plant, which inhibits the plant's ability to adapt to stresses and changes in the environment.
Maintaining healthy populations of dwarf spiraea will require managing and conserving its current habitat. This includes protecting these areas from human disturbance as well as limiting competition by invasive plants. Forestry management practices such as selective cutting to prevent canopy closure and a fire disturbance regime may increase flowering and seed set, thus expanding the genetic diversity of the plant and population numbers throughout its range.
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.