Notions on European orchids

Orchids are "young" plants, and due to the scarcity of fossil evidence, estimating their age of appearance is not easy. Their emergence is therefore placed between 20 and 100 million years ago, while the first flowering plants would have appeared at least 150 million years ago.

 

General Characteristics:

They have a single, unbranched, upright stem and a multiple inflorescence. The stems are smooth or fuzzy and bear the leaves.

The leaves are veined lengthwise and elongated (except for Goodyera repens, which has more complex leaves). All of the leaves arise from the base to form a rosette or are distributed along the stem. Sometimes, they are reduced to their simplest form and become sheathing.

The roots are varied: tubers or rhizomes. In France and Europe, orchids are terrestrial, with roots or tubers remaining underground. The leaves may be permanent or semi-permanent. The stems and flowers only appear for a short flowering period.

The flowers exhibit bilateral symmetry, resembling a face (unlike radial symmetry, as in daisies or roses). There are always three sepals (at the back) and three petals (at the front) that make up the perianth, but their arrangement is complex and offers surprising diversity: each species has its own floral organization, and in some cases, even individual flowers can vary in color or shape.

Of the three petals, the two lateral ones are identical, but the lower middle one is called the labellum and generally points forward (somewhat like a tongue). Often brightly colored and significantly more structured than the other petals, it indirectly aids in pollination by acting as a "landing strip" for insects. During the formation of the floral bud, the labellum is initially at the top, but as the ovary bearing the flower twists (a phenomenon known as resupination), the labellum appears at the bottom. Exceptionally, some flowers or species do not undergo this resupination.

The flower colors are generally red, purple, pink, or white, but there are a few species with yellow flowers. Some flowers may be hypochromatic (partially or almost totally lacking pigmentation), while others may be hyperchromatic with an unusual increase in violet pigments.

 

Habitat:

In Europe, orchids are terrestrial with a root system in the soil, unlike tropical orchids, many of which are epiphytic (having aerial roots and living on branches or tree trunks) or lithophytic (living on rock surfaces). The majority of orchid species prefer limestone and often poor soils (calcareous meadows, wastelands, scrubland, pastures grazed by livestock, or road verges). Some species thrive in wet, acidic soils (partially flooded or seepage-prone meadows, edges of reed beds or marshes) or in shaded forest areas. Orchids are not typically found in cultivated fields or overly rich soils, especially those amended with fertilizers, but orchids may appear after a few years of fallow.

 

Reproduction:

Orchids are sexually reproductive and, except for rare exceptions, require pollinating insects for reproduction. These insects are sometimes of a single species due to their particular morphology, or they may be of multiple species, which increases the chances of pollination. The pollen of orchids is grouped into small masses that stick to the foreheads of insects, which then transfer it to the female organs of another flower. Very few orchids produce nectar (which typically attracts insects), so colors, shapes, and pheromones play the role of attraction. Some species produce seeds without sexual reproduction. Others propagate vegetatively and produce colonies of "clones" around the parent plant by root development, without excluding traditional reproduction.

 

Critical Life and Reproductive Period:

Depending on the species, leaves appear in winter or spring. This is also when habitat maintenance may occur. Many orchids grow in grazed meadows and along the verges of our roads and highways. Only calcareous grasslands, free of tall vegetation that harms the growth and flowering of continental orchids, are ideal for species like Ophrys. The period from February to July is crucial for flowering: plant growth, development of new tubers (formerly and mistakenly called bulbs), or rhizomes occurs through photosynthesis. Cutting leaves can thus hinder plant development for the current year and even for the following one. When a flower stem is cut (mowed, grazed, etc.), only that year's flowering is affected, and the plant does not suffer irreversible damage.

Orchids with tubers (e.g., Orchis, Ophrys) develop from this nutritional reserve. Meanwhile, a second (or even more, in exceptional cases) tuber appears and will constitute the plant's reserve for the following year. Once the cycle is complete, the upper part of the plant deteriorates, and flowers, stems, and leaves disappear. Some more woody stems may remain, and in the following spring, these dead stems can be observed next to new ones. From the new tuber, new leaves appear in autumn or early winter and will lead to a new flowering between January and June, depending on the species and geographical location. Thus, even though it is the same individual reappearing each year, it may slightly shift its position to flower a few centimeters further. Orchids thus have the ability to "migrate" and shift slightly from their original tuber.

A fertilized flower produces several hundred to several thousand tiny seeds. These lightweight seeds can fall near the parent plant or be carried away and colonize another area. Conditions for a seed to germinate into a new plant are minimal. The seed must be slightly buried and encounter the mycelium of a symbiotic fungus to germinate. The seed has no nutritional reserve, and the fungus provides it with nutrients. It often takes several years for a plant to produce flowers.

Increasingly, we see signs along the sides of our roads stating "Late Mowing." This is beneficial for certain grasses but rarely effective for orchids, which develop their seeds over an extended period. Mowing a roadside in May or June (often just before summer break for maintenance teams) does not allow orchids to fully seed. The seed capsules need to dry out, and they only release seeds between June and July. Therefore, mowing should be done after this period.

 

Variability in Species:

• The size of plants varies greatly, with an orchid of the same species measuring less than 10 cm or growing up to 50 cm.

• The number of flowers is not constant: the Venus slipper usually carries one flower, sometimes two, while another species might have 10 or 50.

• The shape of the flowers also shows great variability within a species, but their size tends to be more constant. On the same flower stem, sometimes Ophrys flowers may exhibit different shape characteristics.

• The flower color is usually constant for a species, but the shade can vary. For Ophrys, the markings on the labellum can vary greatly. One species (Dactylorhiza sambucina) can have flowers that are either purple or yellow, with both colors often coexisting.

 

Why is it so difficult to identify an orchid?

Orchids are not very numerous: about 90 species and a total of 160 species and subspecies in France, but the variability from one plant to another can make identification very challenging. Species within the same genus can hybridize, leading to infinite possible combinations, as these hybrids are usually fertile and create new plants that can also hybridize endlessly. It is not always easy to distinguish between genetic diversity and hybridization. Some genera (remember, these are arbitrary classifications created by botanists, and nature doesn't care about our reasoning) can also hybridize between different genera: for example, species from the Anacamptis and Orchis genera.

Fortunately, some genera are represented by just one species in our territory (e.g., Cypripedium calceolus) and, despite geographical isolation, populations in Haute-Marne and Côte d'Or have distinct morphologies regardless of the region.

Some animal species are younger than our orchids and, due to genetic evolution, are no longer capable of hybridizing, leading one to wonder why plant species haven't developed such genetic barriers. One possible explanation lies in the "awareness" that animal species have in selecting their mates, whereas flowering plants depend on insects, which primarily ensure pollination and "decide" which plants will pair. This results in much more genetic mixing, allowing plants to remain interfertile for much longer periods. Only geographic isolation can enable a group of plants from the same species to evolve rapidly, as new genetic combinations spread quickly.

Practically speaking, to identify orchids, guides or websites may be consulted. Botanical excursions and interactions with other enthusiasts can also help improve knowledge. However, it is important to remember that there are few absolute truths, and in the face of highly diverse flowers, one person might classify a specimen as one species, while another may place it in a different one. A strong conviction does not make something true! Some authors may multiply species, creating confusion, while others may take a simpler, more cautious approach by grouping individuals into one species with non-discriminating characteristics.

 

How many orchids are there in France?

The different genera with the most common species are listed below.

In France, there are 25 genera with about 160 species + subspecies.

13 genera are represented by only one species, often rare to very rare. 10 genera are represented by 3 to 50 species.

The validity of certain species is debated; some may only be subspecies, regional varieties, or geographically isolated populations with different flowering times. In principle, a species is defined by its genetic isolation and lack of natural hybridization with others. At the European level, many species within the same genus spontaneously hybridize, and even different genera can hybridize, leading to legitimate questions about whether we should name an orchid as soon as it exhibits morphological differences or a shifted flowering time. This site does not aim to fuel such debates, but will adhere closely to the most current nomenclature to avoid confusing the reader in their research and identification of species.

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Genus Orchis (Orchis militaris, Orchis purpurea, Orchis simia, Orchis anthropophora, Orchis mascula). About 10 species in France.

 

Genus Ophrys (Ophrys apifera, Ophrys araneola, Ophrys aranifera/sphegodes, Ophrys fuciflora, Ophrys insectifera, Ophrys scolopax). About 13 species, but many subspecies in France. From common to very rare, with many species often being regional variations.

 

Genus Dactylorhiza (Dactylorhiza fuchsii, Dactylorhiza maculata, Dactylorhiza incarnata, Dactylorhiza sambucina, Dactylorhiza viridis - formerly Coeloglossum viride). About 5 species in France but a total of over 30 species + subspecies. From common to rare.

 

Genus Epipactis (Epipactis atrorubens, Epipactis helleborine, Epipactis muelleri). 10 species and a little more than 20 species + subspecies, from common to rare and regional.

 

Genus Anacamptis (Anacamptis pyramidalis, Anacamptis morio). About 7 species in France, but double that number in species + subspecies. Common in almost all regions.

 

Genus Serapias (Serapias lingua, Serapias vomeracea). About 8 species, more or less rare and localized.

 

Genus Cephalanthera (Cephalanthera damasonium, Cephalanthera longifolia, Cephalanthera rubra). 3 species, generally common but sometimes regional.

 

Genus Gymnadenia (Gymnadenia conopsea, Gymnadenia rhellicani). 8 species in France, more or less rare and localized.

 

Genus Platanthera (Platanthera bifolia, Platanthera chlorantha). 3 species in France. Common and widespread for the species mentioned.

 

Genus Neotinea (Neotinea maculata, Neotinea ustulata, Neotinea tridentata, Neotinea lactae). About 6 species, more or less rare or localized.

 

Genus Himantoglossum (Himantoglossum hircinum, Himantoglossum robertanium). 2 common species, one of which is localized.

 

Genus Neottia (formerly Listera ovata, Listera cordata, and Neottia nidus-avis). 3 species, including 1 common and 1 regional.

 

Genus Spiranthes (Spiranthes spiralis). 2 rare species but geographically widespread.

Genus Limodorum (Limodorum abortivum). 2 species, one common and one regional.

Genus Cypripedium (Cypripedium calceolus = Venus’s slipper). Only 1 species in France. Rare and localized.

Genus Goodyera (Goodyera repens). 1 common species.

Genus Herminium (Herminium monorchis). Only 1 species in France. Rare and localized.

Genus Epipogium (Epipogium aphyllum). 1 rare species.

Genus Liparis (Liparis loeselii). 1 rare species.

Genus Corallorhiza (Corallorhiza trifida). 1 rare species.

Genus Hammarbya (Hammarbya paludosa). 1 rare species.

Genus Gennaria (Gennaria diphylla). Only 1 species in France. Extremely rare (Corsica).

Genus Chamorchis (Chamorchis alpina). Only 1 species in France. Rare and localized.

Genus Traunsteinera (Traunsteinera globosa). Only 1 species in France. Rare and localized.

Genus Pseudorchis (Pseudorchis albida). Only 1 species in France. Uncommon and moderately widespread.

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General Information about Ophrys:

Ophrys are jewels of elegance among European orchids. The plants have an average height (usually 10 to 30 cm), but can occasionally reach 70 to 80 cm (Personal observation of Ophrys apifera and Ophrys insectifera). The flowers are small, barely the size of a fingernail, non-nectariferous, and appear to have very little pollen: two pollinia that aggregate the entire pollen. The flowers are few in number: often between 10 and 15. The labellum (the forward petal) is particularly developed and complex. Normally convex, it gives the impression of a full shape, but it is actually a fine, curved petal adorned with more or less marked lateral swellings, most often hairy. The labellum is colored on the front, but on the back, it usually remains a solid whitish to beige color. It is often slightly tilted and forms an angle with the other petals, making it more visible to flying insects... and to orchid hunters! Each species of Ophrys has its own petal and sepal colorations, labellum shapes, and patterns on these labella. However, there are infinite variations that can complicate identification, and hybridizations are always possible... So, it often leads to discussions about whether one is dealing with a species, a subspecies, or a regional variety.

It is often said that Ophrys "mimic" insects, which is why their old vernacular names include Ophrys abeille (bee orchid), Ophrys guêpe (wasp orchid), Ophrys mouche (fly orchid), etc. This "resemblance" is believed to attract male insects that attempt to mate with these apparent females and, in doing so, transfer pollen while moving from flower to flower, ensuring pollination. This is, if not a folly, at least far from the truth, as insects are quite adept at recognizing their potential mates visually and do not attempt to mate with females of a different species. It is primarily the pheromones secreted by Ophrys that attract and deceive them. An evolutionary process has allowed insects and Ophrys to slowly form a pollinator relationship: often, each Ophrys is pollinated by only one or two species of hymenopterans... and the flowers of Ophrys do not resemble their pollinators at all! Neither the shape nor the patterns of the labellum are similar! Nor, to a large extent, is the size. What is certain is that male hymenopterans are deceived when they land on the labellum. Intoxicated by the pheromones and likely reassured by the hairiness of the labellum, they attempt to copulate with it and end up with one or both sticky pollinia, usually on their forehead. If they quickly realize the trick, they often attempt another mating with another flower, more or less nearby. In the meantime, the pollinium has shifted, and during this new attempt, it pollinates the female organs of the orchid. If the insect gets tired of being deceived, it may change flower species for a true pollen source or simply find a real mate of its own species! There is thus a high risk that all the pollen is lost for reproduction! The flowers on an orchid plant are rarely all fertilized.

Some Ophrys are called pseudophrys and show slight morphological differences. They are pollinated by their own hymenopterans, which try to mate in an inverted position, turning their back on the pollinia. These then stick to their back or the tip of their abdomen. By visiting another Ophrys flower, still in the same position, they also ensure fertilization. It is difficult to know if it is the Ophrys species that induces the position of its pollinator or if the pollinator adopts a more natural position for its own species.

Ophrys are often plants that favor calcareous and dry soils, more or less grassy. They thrive in fallow land and scrublands but not in forests or overly shaded areas. Like Orchis, their roots are tuberous. However, I have observed Ophrys apifera for several consecutive years in a location of Dactylorhiza elata, with their roots submerged in a generous spring, likely for a large part of the year (Personal observation: La Bastide Pradines, Aveyron).

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