H. pulchrum is a dainty, rhizomatous perennial plant growing nine to eighteen inches high. It has erect smooth stems without ridges or wings. It has a few opposite pairs of untoothed, heart-shaped leaves that half clasp the stem. They are dotted with transparent spots and often have inrolled margins. The terminal inflorescence has rich yellow flowers. Each of these has five small, broad, blunt sepals with black dots on the margins. The five petals are red beneath and have red and black dots on the margins. There are three styles and many stamens with orange anthers in three bundles. The fruit is a dehiscent capsule.
H. pulchrum is found growing in Austria, Belgium, Britain, Czechoslovakia, Denmark, Finland, France, Germany, Ireland, Italy, Netherlands, Norway, Poland, Portugal, Spain, Sweden and Switzerland. It is found in suitable habitats throughout the United Kingdom. It has been introduced to New Zealand where it has spread across South Island and the southern part of North Island.
- McKlintock, D. and R. S. R. Fitter. The Pocket Guide to Wild Flowers. (1956) Collins, London. P28.
- Slender St John's Wort West Highland Flora. Retrieved 2011-09-14.
- Hypericum pulchrum: Slender St. John's-wort British wild flowers. Retrieved 2011-09-14.
- Hypericum pulchrum Flora Europaea. Retrieved 2009-09-15.
- Hypericum pulchrum L. Flora of New Zealand. Retrieved 2011-09-14.