True lover's knot

Description:

Small herbaceous plant with characteristic four leaves with parallel nerves - and, unusual for monocots, a visible network of secondary nerves in between the main ones. The fruit, seen here, is a solitary berry, dark blue in color and somewhat blueberry like. Flowers are discreet and solitary mainly yellow-green, with narrow greenish threadlike petals, green petaloid sepals, eight stamens, and a round purple to red ovary in the center - it can be seen in one of my previous spottings, here: https://www.projectnoah.org/spottings/50...

Habitat:

Eurasian species, found in forests growing in shadow, and found up to 2000m of altitude. Here, seen in a small valley in Jura mountains. The valley is surrounded by a coniferous forest, and is composed of grassland, peatland and a small glacial lake.

Notes:

All parts of this plant are toxic, containing two mucose-irritaing substances, paridine et parastyphnine (whatever that may be...).