Circaea lutetiana L.

Plant Type

Circaea lutetiana L. is a perennial herbaceous plant.

Stem and Leaf Arrangement

It has slender green stems that bear opposite, simple leaves.

Height

It reaches 20 cm to 60 cm in height, and rarely grows as tall as 75 cm.

Flowering Period

Its white flowers bloom in summer.

Leaf Morphology

The base of each leaf is rounded or slightly notched, the leaf narrows gradually to a pointed tip, and edges are not strongly toothed but sinuate.

Leaf Stalk Hairs

Leaf stalks are equally hairy all around.

Flower Structure

Each flower has 2 notched petals, 2 stamens and a 2-lobed stigma.

Flower Arrangement

Open flowers are well spaced along the stalk, and there are no bracts at the base of individual flower stalks.

Pre-Fruiting Stalk Position

Before fruiting, flower stalks bend to angle downwards.

Fruit Cell and Seed Characteristics

The fruit has 2 equal cells and usually produces viable seed.

Fruit Morphology and Dispersal

It is a small bur measuring 3.5–5mm, a structure that helps the plant disperse its seeds via zoochory.

Winter Growth Habit

In winter, all above-ground aerial parts of the plant die off, leaving an underground rhizome.

Hybridization

This species can hybridize with Circaea alpina, producing sterile offspring that persists as vegetative colonies.

Native Range

This plant is native to Europe, Middle Asia, and Siberia.

Taxonomic Revision of North American Populations

Populations that were previously placed in this species from North America are now classified as a separate species, Circaea canadensis.

Habitat

It grows in woods in deep shade and moist environments on nitrogen-containing clay.