Authors: C. Stace, R. van der Meijden (ed.) & I. de Kort (ed.)
Search
Scientific name:

Hypericum tetrapterum

Vernacular name:

St John's-wort, Square-stalked


Use the links below to jump to previous and next taxa in a text browser:
Hypericum undulatum - St John's-wort, Wavy
Hypericum humifusum - St John's-wort, Trailing

Square-stalked St John's-wort

Scientific name: Hypericum tetrapterum Fr.

Diagnostic features
Erect rhizomatous glabrous perennial.
Stems to 60cm, square in section, with distinct wings 0.25-0.5mm wide.
Leaves with many small translucent glands.
Flowers 9-13mm across.
Petals pale yellow.
Black glands on leaves and sometimes petals or sepals, sessile.

Chromosome number: 2n=16.

Habitat
Native; marshes, riverbanks and damp meadows.

Distribution
Frequent throughout British Isles except North Scotland.

This species is keyed out on Page 3871 in the Text Key.

Hypericum tetrapterum
Description provides information about characters, distribution and habitat of the selected species or higher group. You can search using vernacular or scientific name.
St John's-wort, Square-stalked
General introduction, overview of the species treated and functionality of the site
A tree, picture gallery and alphabetical lists provide access to the species and higher groups
Descriptions of species
Descriptions of higher groups
Identification keys
Atlas
Glossary
Literature references
Test your knowledge of the species treated
Concise explanation of the BIS program
Authors of and contributors to this project
Return to the main index of the World Biodiversity Database