St. Andrew's Cross
State Status: N
PBS Status: Pennsylvania Threatened (PT)
Global Rank: G5T4
State Rank: S2
Did You Know?
This species is distinctive for its spreading, four-petaled flowers that almost look like a dragonfly.
St. Andrew's cross (Hypericum stragulum) is a low-growing, deciduous shrub with erect stems up to 30cm tall. The leaves are oppositely arranged, 2-3cm long, untoothed on the margin, oval or lance-shaped and usually widest above the middle, rounded at the tip and tapered toward the base. The flowers, appearing in July and August, are bright yellow and have four narrow petals, which are about 9mm long and configured in a cross-like pattern, and are subtended by two green sepals. The fruit is a many-seeded capsule.
Imperiled in the nation or state because of rarity due to very restricted range, very few populations (often 20 or fewer), steep declines, or other factors making it very vulnerable to extirpation from the nation or state.
The PA Biological Survey (PABS) considers St. Andrew's cross to be a species of special concern, based on the few occurrences that have been recently confirmed. It does not have a PA legal rarity status, but has been assigned a suggested rarity status of Threatened by PABS. About ten populations are currently known from the state.
It grows in dryish, open places, such as grasslands, successional clearings, thickets, open woods, and serpentine barrens.
Flowers July - August
The populations of St. Andrew's cross in the state are threatened by human-related habitat loss, natural succession, invasive species, and indiscriminate application of herbicides.
Given the preference of the species for open habitats, active management - such as fire, mowing, or invasive species removal - is often required to maintain the proper successional stage and ecological conditions for the species to thrive.
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.