Bird's Nest Orchid
- Written also: Bird’s-nest Orchid
- Family: Orchid Family – Orchidaceae
- Growing form: Perennial herb. Root system abundant, roots thick, intertwining. Parasitic plant, symbiotic with mushroom roots.
- Height: 10–30 cm (4–12 in.). Stem yellowish brown, opaque, non-chlorophyllous.
- Flower: Perianth irregular (zygomorphic), yellowish–light brown, approx. 10 mm (0.4 in.) wide. Tepals 6, in 2 whorls, of which one elaborated into labellum. Labellum under perianth, spurless, bowl-shaped base, 2-lobed tip. Androecium and gynoecium fused into a column, stamens 1, stigmas 2. Inflorescence adense, abundant-flowered spike, flowers with honey scent.
- Leaves: Alternate, stalkless; scaly, non-chlorophyllous leaves 4–5.
- Fruit: Egg-shaped capsule, overwintering, seeds tiny, like dust.
- Habitat: Broad-leaved forests, grove-like forests. Calciphile.
- Flowering time: June–July.
- Endangerment: Near threatened, protected in all of Finland except the Åland Islands.
All orchids depend on mushrooms, at least in the early stages of their lives, as they nourish the sprouting seeds. Bird’s nest orchid is almost non-chlorophyllous and is unable to produce its own energy even for breathing, so it needs the mushroom to take care of its nutritional demands throughout its whole life cycle. Its roots are connected to the mushroom’s filament network, which breaks down forest litter and other dead vegetable matter into nutrition. The mushroom delivers sugars and other nutrients, but it is unclear if the mushroom makes use of anything from the orchid – it might be a parasite, or it might provide e.g. amino acids that the mushroom is itself unable to synthesize.
Bird’s nest orchid’s brown or swarthy yellow flowers do not look particularly attractive, but they emit quite a powerful, sweet, musty odour. The fragrance and nectar that is emitted during warm weather invites many kinds of flies in for a meal and to pollinate the flowers (which can also be self-pollinating). After flowering the flower shoot, root and most of the rhizome dies, but the buds at the tip of the root develop into new bird’s nest orchids. Propagation by seed is a lottery – if the seed doesn’t land on suitable soil beside its companion mushroom Rhizoctonia neottiae the plant will not get beyond the germination phase.
Finland’s three non-chlorophyllous orchids – bird’s nest orchid, ghost orchid (Epipogium aphyllum) and coralroot orchid (Corallorhiza trifida) – are not related to each other at all, but they have independently developed the same way of life. Bird’s nest orchid’s closest relatives are twayblades (belongig to genus Listera), and they are sometimes even included as a member of this genus.