Neottia ovata

Morphological description

Perennial herbaceous plant belonging to the Orchidaceae family, characterized by a cylindrical and tuberous rhizome, from which filiform and sinuous roots develop. The stem is erect, robust, and cylindrical, with a height varying between 40 and 60 cm. The surface of the stem may present a slight whitish pubescence especially above the leaf insertion and varies in color from green to brownish.

The leaves are generally arranged oppositely at about one-third of the stem height and are ovate, 5-10 cm long, thick and glabrous, with a glossy upper surface. The veins are parallel and well visible. Rarely, 3-4 small additional leaves can be observed, higher than the two main ones. The bracts are poorly developed, triangular in shape, and shorter than the floral peduncles.

The inflorescence is a loose raceme, cylindrical or cylindrical-conical in shape, bearing slightly pedunculated, odorless flowers, greenish-yellow in color. Each flower is composed of ovate and acute tepals 8-10 mm long, which are connivent forming a sort of hood. The labellum is linear, elongated and pendulous, yellow-greenish in color, with a bifid apex formed by two narrow and acuminate slightly divergent lobules. At the base of the labellum there is a shiny cavity containing nectar, essential for pollination. The structure lacks a spur. The ovary is inferior, globose, pubescent and supported by a twisted peduncle.

The fruit is a capsule containing extremely minute seeds, typical of orchids, which allow effective dispersal by wind.

Habitat and distribution

It is a species widespread throughout Italy, although less frequent in the central-southern regions. It grows mainly in fresh broadleaf woodland environments, but can also be found in spruce forests, alpine pastures, shrubs and clearings, as well as along path margins. It rarely colonizes meadows with moist soil. It tolerates a wide range of soil conditions, growing on both acidic and basic soils.

Its altitude range varies from 0 up to 1900 meters above sea level, thus covering a wide altitudinal range. In the Mediterranean context, the species is mainly present in areas with temperate and humid climates, particularly in shady and fresh woods.

Flowering period

Flowering generally extends from May to August, with possible variations related to latitude and altitude. In more northern territories or high mountains, flowering may start later and end within the summer.

Ecology and pollination

Common Twayblade presents an interesting reproductive strategy, mainly based on entomophilous pollination by hymenopterans parasitic on insects and plants. Insects are attracted by the nectar contained in the cavity at the base of the labellum and, landing on it, touch the tip of the rostellum, which allows the release of a sticky liquid. This liquid adheres to the pollinia, which thus attach to the pollinating insects.

The mechanism is further refined by the fact that the rostellum, once activated, moves to cover the stigma, preventing self-pollination. When the insect moves away, the rostellum returns to its original position. The plant also propagates vegetatively through lateral shoots originating from the rhizome, thus ensuring local expansion even in the absence of pollinators.

Seed dispersal occurs through the wind, favored by their tiny size, which allows wide diffusion.

Curiosities and traditional uses

Medicinal or traditional food uses for this species are not widely documented. However, like all wild orchids, it is subject to legal protection as a species at risk, included in the Washington Convention and protected by specific regional laws, such as in Lombardy.

From a naturalistic point of view, the presence of this orchid is an indicator of good quality forest habitats and balanced ecosystems.

Etymology

The generic name "Neottia" derives from Greek and means “bird’s nest,” referring to the particular intertwined conformation of the roots, which indeed resemble a nest. The specific epithet "ovata" refers to the ovate shape of the leaves, a distinctive characteristic of the species.

The Italian common name "Common Twayblade" derives from the previous genus "Listera," with the addition of "maggiore" to distinguish it from Listera minore (Neottia cordata), which is smaller and has different leaf characteristics.

Sources

• Acta Plantarum - Flora delle regioni italiane (scheda di Marinella Zepigi)