Weed Science & Agronomy
INRA-Dijon
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Unité de Malherbologie & Agronomie Weed Science & Agronomy INRA-Dijon |
Bayer Code : hyppe
Synonym(s) of Sc. name: Hypericum noeannum Boiss.
Classification: Guttiferae, Dicotyledonous
Common name: perforate st. john's-wort
Synonym(s) of Common name:
Name per country: DE : Echtes Johanniskraut ; ES : hierba de san juan ; FR : millepertuis à feuilles perforées ; IT : erba di San giovanni comune ; PT : milfurada ; EN : perforate st. john's-wort ; NL : sint-janskruid ;
Biological type: Biennial, Perennial
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- Cotyledons lengthened spoon-shaped.
- Leaves entire, elliptic to ovate, entire-margined.
- Height: 20-80 cm. Plant glabrous.
- Stem erect, terete, with 2 raised lines, often simple and branched above.
- Leaves 8-30 mm, opposite with translucent dots and black-dotted margins. Lower leaves rounded or ovate, sessile ; upper leaves obovate or ovate, lengthened, short-stalked.
- Flowers yellow with numerous stamens, in many-flowered cymes. Petals denticulate only on one side, black-dotted on borders.
- Fruit : capsule ovate, 2 to 3.5 mm in diameter; seeds black, 1-1.3 mm, globose, minutely warty.
- Perennial plant propagates with buds from rhizomes and sometimes from roots. Toxic for the cattle in pastures. Rare in crops. Successfull biological control in Australia since 1943 thanks to several species of coleopterons. Plant discutient, stimulant, vermifuge, a very good quick vulnerary. There is a dyeing component yellow in water and red in oil.
- Risk of confusion with Hypericum humifusum L., Lythrum junceum Banks & Solander. (at seedling stage).
- Biological type: Biennial or perennial.
Mistake with: Hypericum humifusum , Lythrum junceum
Ecological profile (click on flags):
Present
Present
Present
Rare
Present
Present
