- Scientific name: Hypericum stragulum
- Species of Greatest Conservation Need (MA State Wildlife Action Plan)
- Endangered (MA Endangered Species Act)
Description
St. Andrew’s cross is a low shrub (up to 30 cm [1 ft]) of the St. John’s-wort family (Clusiaceae), known for its distinct flower shape. The four bright yellow petals make an oblique cross at the stem tips, which contrast against the dark green foliage. St. Andrew’s cross is often found in clumps in dappled sunlight and forest edges as a low ground cover. The woody stems are slender and reddish. The leaves are evergreen, opposite, and sessile, 1-3 cm (0.4-1.18 in) in length; they are slightly waxy and narrowly oblong in shape, with smooth margins. Solitary yellow flowers bloom at the branch tips and uppermost axils in mid-summer and are insect-pollinated. The flowers are small (8-11 mm [0.31-0.43 in]), with narrow petals and numerous stamens. Once fertilized, the sepals enclose the swelling fruit. The emerging egg-shaped capsule contains many small round, black seeds. Seed capsules split open when mature. Dry seed capsules turn reddish brown and can remain on the plant through the winter. St. Andrew’s cross is easily identifiable when in flower due to the oblique-cross shape of the petals. This species flowers throughout the summer.
The shrubby habit and unique flower shape distinguish this species from others in its genus.
Life cycle and behavior
Population status
St. Andrew’s cross is listed under the Massachusetts Endangered Species Act as Endangered. All listed species are protected from killing, collecting, possessing, or sale, and from activities that would destroy habitat and thus directly or indirectly cause mortality or disrupt critical behaviors. MassWildlife’s Natural Heritage & Endangered Species Program has 15 records from Nantucket County. Eight of these records have been observed within the last 25 years.
Distribution and abundance
The range of St. Andrew’s cross extends from Florida across the mid-Atlantic, north to Massachusetts and west to Texas. Massachusetts is at the northern part of its range.
Distribution in Massachusetts. 2000-2025. Based on records in the Natural Heritage Database.
Habitat
In Massachusetts, St. Andrew’s cross inhabits dry, sandy soils of early succession, disturbed habitats near the coast. Known habitats in Massachusetts include path and woodland edges, open shrubby thickets, and the upland fringes of wetlands. St. Andrew ’s cross requires full to filtered sunlight, and sometimes occupies canopy openings. It is frequently associated with arrowwood (Viburnum dentatum), bayberry (Morella caroliniensis), lowbush blueberry (Vaccinium angustifolium), little bluestem (Schizachyrium scoparium), beaked hazelnut (Corylus cornuta), scrub oak (Quercus ilicifolia), fox grape (Vitis labrusca), and sassafras (Sassafras albidum).
Healthy habitats are vital for supporting native wildlife and plants. Explore habitats and learn about conservation and restoration in Massachusetts.
Threats
Habitat loss and succession are the major causes for decline of St. Andrew’s cross. Slow germination rates may also be a major contributor to the status of this species.
Conservation
This early succession species requires some level of disturbance to proliferate, and adequate sunlight. Mowing during dormancy has been shown to increase flower production and plant density. Path and forest edges where this species occurs may require active management to prevent over-shading by taller, more aggressive woody plants. All active management of rare plant populations (including invasive species removal) is subject to review under the Massachusetts Endangered Species Act and should be planned in close coordination with MassWildlife’s Natural Heritage Endangered Species Program.
References
Fernald, M.L. 1936. The varieties of Ascyrum hypericoides. Rhodora 38: 433.
Contact
| Date published: | April 29, 2025 |
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