Paris quadrifolia

 The true lover's knot. From China, throughout the southern region, an equivalent of a trillium in the US. In spring, the 40cm stems carry a whorl of leaves, with a flower atop, with whiskers.It occurs in temperate and cool areas throughout Eurasia, from Spain to Yakutia, and from Iceland to Mongolia. It prefers calcareous soils and lives in damp and shady places, especially old established woods and stream banks. I have mine in neutral or slightly acidic woodland and it has spreads well (but slowly). Seed takes a couple of years to germinate, if at all. No natural seedlings, yet all my other woodlanders make pups. Rare and large pots. Only four for sale. For nerds. Late spring emergence, not up until mid October.  Average, well-drained, woodland soil. Sometimes paris has the pesky habit of skipping above-ground growth for the first year after transplanting, so don't give up hope. There are one or two strong buds on each potted eice.

Seed capsule. By Ivar Leidus - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=95639669

Last image by MurielBendel - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=43588620