Hypericaceae: St John’s Wort Family

Creeping St John’s Wort – Hypericum anagalloides

Blooms:

June–Aug

Plant Height:

3–30 cm

Flower Size:

Small

Origin:

Native

Habitat:

Wet places

Notes:

A low-growing plant, spread by runners (stolons) and sometimes forming dense mats.  Flowers are small and (usually) golden yellow.  Leaves are green, sometimes red-tinged, oval to rounded and clasping the stem.

Klamath Weed – Hypericum perforatum subsp. perforatum

Blooms:

May–Aug

Plant Height:

30–120 cm

Flower Size:

Medium

Origin:

Europe

Invasive?

Yes – moderate

Habitat:

Open, disturbed areas, many communities

Notes:

This is an invasive weed which is poisonous to livestock,  often found growing in large clumps.  Each stem has many (25–100) bright yellow, 5-petaled flowers, which may have a row of tiny black dots along the petal margins.  The leaves provide an important diagnostic feature; they appear to be perforated, the result of the presence of many small, clear oil glands.  Garden varieties with larger blossoms sometimes escape and naturalize.  At first sight the leaves bear a resemblance to French Broom (Genista monspessulana), but the plants are unrelated.  Like other Hypericum species, this is sometimes called St. John’s Wort, and has uses in traditional medicine.