Hypericum calycinum is a species of prostrate or low-growing shrub in the flowering plant family Hypericaceae.

Hypericum calycinum is a low, creeping, evergreen woody shrub (classified as a subshrub or shrublet[4]) to about 1 m tall and 1–2 m wide but often smaller.

[9] Hypericum calycinum is an economically valuable plant in North America, commonly used for ornamental reasons and landscaping.

This shrub grows through underground stems and is typically grown as ground cover or to stabilize soil on hills and requires low maintenance.

[13] Research has shown that the UV pigments of the Hypericum calycinum flower stave off predators such as mites and aphids.

One type of DIP (dearomatized isoprenylated phloroglucinols), a category of pigments alongside flavonoids, was found to be toxic to a caterpillar as well.

Unlike the rest of the genus, H. calycinum does not have hypericin, which causes photosensitization, which causes the side effects of flush, fatigue, and pruritus when used in drugs.