Epipactis microphylla

Epipactis microphylla is a terrestrial, geophytic, and perennial forest orchid species. It is a mycoheterotrophic species (with both chlorophyllous and achlorophyllous individuals) that depends on a close symbiotic association with ectomycorrhizal fungi for its survival throughout all its life stages. Notably, among these fungi, truffle species of the genus Tuber, such as Tuber excavatum, have been identified in its roots. It is a plant characteristic of temperate and sub-meridional zones.

Morphological description: Morphologically, it is a densely pubescent herb reaching between 15 and 30 cm in height, growing from a short rhizome. The stem can be pale green, gray, or have a violet hue. Its leaves (between 3 and 10 per plant) are very small, lanceolate in shape (1 to 5 cm long by 0.5 to 1.5 cm wide), dark green to violet, erect or spreading, and always shorter than the internodes of the stem. The inflorescence is loose, oriented almost to one side, and can produce from a few to a maximum of 40 flowers. The flowers are green or violet, smell of vanilla, and hang downwards or remain almost horizontal, appearing open or only partially open. The ovary is very hairy and measures 7 to 11 mm, while the capsules containing the seeds are between 13 and 18 mm.

Pollination and life cycle: Flowering occurs between June and August. It is particularly notable for being an autogamous species (self-pollinating), which allows it to colonize and survive in forests where pollinating insects are very scarce, though it still retains some residual traits of allogamy. To achieve autogamy, the flower has reduced the size of its stigma, and its vispidium (the adhesive part that would normally attach to insects) has become ineffective or is only functional at the beginning of the flowering stage. The pollinia are powdery and easily detached, allowing them to directly contact the stigma surface to fertilize the flower without external aid.

Habitat and distribution: It is a Euro-Caucasian and Hyrcanian species. It is distributed across much of Europe and Southwest Asia, ranging from Andalusia, Turkey, Crimea, and the Caucasus region, to northern Iran and the Caspian Sea. Despite its widespread European distribution, it is notably absent from the British Isles and Scandinavia. Recently, its distribution area has also been found to extend to North Africa, with a population discovered in the Djebel Babor mountains in northeastern Algeria. Its main habitat is broadleaf forests (and sometimes coniferous forests), where it grows in shady places or forest margins on calcareous soils, from lowlands to mountain areas.

Conservation status: At the European and Mediterranean level, a progressive reduction of its suitable habitats due to climate change is projected in the coming decades. Legally, the species benefits from certain regional and international protections: it is protected under the international CITES agreement; classified as Vulnerable (VU) in Slovakia and Endangered in the Czech Republic; and in Andalusia, the red list classifies it as Near Threatened (NT).