New York Natural Heritage Program
Creeping St. John's-wort
Hypericum adpressum Raf. ex W. Bart.

General Description [-]
Creeping St. John's wort is a rhizomatous herbaceous plant that grows 3-8 decimeters tall. It usually occurs in large clumps with many stems. It has opposite, linear, to narrowly elliptic leaves that are 3-6 centimeters long and 5-10 millimeters wide, 4-6 times as long as wide. Each leaf has a tiny white point at the tip and is tapered at the sessile base. The margins are without teeth and turned under. There are usually many flowers in the inflorescence. The sepals are lanceolate to ovate and 2-7 millimeters long, widest at or below the middle. The bright yellow petals are 6-8 millimeters long. The fruit is a one-chambered capsule that is 4-6 millimeters long and gradually narrowed to the beak.

Best Life Stage for Proper Identification [-]
Even though these can be identified by their leaves in their pondshore habitat it is best to identify them in flower or fruit.

Similar Species [-]
Hypericum ellipticum looks the most like this species but its leaves are flat and not turned under on the margin and the tips are not pointed but rounded. They are only 2-3 times as long as wide. The sepals are widest above the middle. They both are plants of wet places, rhizomatous, and with styles that are not separate.
Creeping St. John's-wort Images
click to enlarge
The Best Time to See
The plants begin flowering in July and are visible through August. Fruits are visible from late August through early October.
Flowering Fruiting
The time of year you would expect to find Creeping St. John's-wort flowering (blue shading) and fruiting (orange shading) in New York.