- Name also: False Lily of the Valley
- Family: Asparagus Family – Asparagaceae
(formerly Lily of the Valley Family – Convallariaceae)
- Growing form: Perennial herb. Rootstock long, thin, branched. Forms stands.
- Height: 5–20 cm (2–8 in.). Stem upper part short-haired.
- Flower: Perianth regular (actinomorphic), white, under 1 cm (0.4 in.) wide; tepals four, 2–3 mm (0.08–0.12 in.) long. Stamens 4, approx. 1.5 mm (0.06 in.) long. Gynoecium fused, a single carpel. Inflorescence a quite dense, 8–20-flowered raceme terminating stem, flowers short-stalked, fragrant.
- Leaves: 2(–4), alternate (vuorottain), stalked. Base sheathed. Blade cordate, sharp-tipped, parallel-veined, underside sparsely haired, with entire margins. 2 light-coloured, scaly bracts at base of stem.
- Fruit: Roundish, initially greyish green, red-spotted, a dark red, approx. 6 mm (0.24 in.) wide berry when ripe.
- Habitat: Dry, young and grove-like forest heaths, broad-leaved forests, forest margins, grazing land, stream banks, bogs.
- Flowering time: May–June.
May lily’s scientific name Maianthemum, ’May flower’ refers to its flowering time while its species name bifolium refers to the fact that it has two leaves, although it might sometimes have three or even four. May lily grows in almost all of Finland, including Lapland, although it gets rarer north of Rovaniemi. The species thrives best in broad-leaved heath forests and is so characteristic that it lends its name to the type of forest it prefers. It avoids more barren forest heaths, although it can also grow sparsely alongside wild bilberry bushes on young moors. It also doesn’t thrive in more fertile broad-leaved forests, and its appearance indicates that the soil is poor in nutrition compared to the best hardwood forests. May lily is sensitive to frost and fierce, direct sunshine. It has specialized in growing with fir trees as they offer shade and protection from night frost.
One of May lily’s most important pollinators seems to be flies, but only around a quarter of the flowers produce berries. The berries are sickly sweet, which can tempt especially sweet-toothed children to taste them, but they contain compounds that affect the heart, and even a few grams can be dangerous. Luckily the small picker’s patience will run out before the fateful level has been consumed, and the poison can be dealt with with pills and causes nothing more than nausea. Birds are not affected by the poison, but even so they are not great fans of the berries. Often stems that are peeping up through the first snow still have berries on them. It seems that birds eat them only when there is not much else on offer. There is not usually so much snow in the middle of dense fir thickets, so birds can eat the berries throughout the winter right up until the spring. Birds that eat the berries spread the seeds which sprout in a suitable environment and form patches.