''Cephalanthera damasonium'', the white helleborine, is a species of

orchid Orchids are plants that belong to the family Orchidaceae (), a diverse and widespread group of flowering plants with blooms that are often colourful and fragrant. Along with the Asteraceae, they are one of the two largest families of flowering ...

. It is widespread across much of

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located enti ...

, the

Middle East The Middle East ( ar, الشرق الأوسط, ISO 233: ) is a geopolitical region commonly encompassing Arabia (including the Arabian Peninsula and Bahrain), Asia Minor (Asian part of Turkey except Hatay Province), East Thrace (Europ ...

and Asia. ''Cephalanthera damasonium'' is the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen( ...

of the genus '' Cephalanthera''.

Description

''Cephalanthera damasonium'' is a herbaceous plant, reaching a maximum height of about 60 cm. Leaves are ovate, becoming narrower higher up the stem, with parallel venation. It has white flowers which never fully open. Each shoot can carry up to 16 flowers. Across its range this species flowers May–June. It is a perennial species which tends not to spread vegetatively.Online Atlas of the British and Irish Flora
/ref> This species is differentiated from the similar and closely related ''

Cephalanthera longifolia ''Cephalanthera longifolia'', the narrow-leaved helleborine, sword-leaved helleborine or long-leaved helleborine, is a rhizomatous herbaceous perennial plant in the family Orchidaceae. It is native to light woodland, and widespread across Europ ...

'', by comparing the leaves. The rarer ''Cephalanthera longifolia'' has longer, narrower leaves.

Distribution and habitat

Found in shady lowland forest with little undergrowth, especially under beech trees, occasionally spreads onto chalk scrub. Can colonise new beech forest quite quickly. Requires a well-drained soil above chalk or oolitic limestone. This species is found in Europe from

England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe ...

and Sweden to

Russia Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-eigh ...

and

Iran Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkm ...

; also

Bhutan Bhutan (; dz, འབྲུག་ཡུལ་, Druk Yul ), officially the Kingdom of Bhutan,), is a landlocked country in South Asia. It is situated in the Eastern Himalayas, between China in the north and India in the south. A mountai ...

India India, officially the Republic of India ( Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the ...

Myanmar Myanmar, ; UK pronunciations: US pronunciations incl. . Note: Wikipedia's IPA conventions require indicating /r/ even in British English although only some British English speakers pronounce r at the end of syllables. As John Wells explai ...

and

Yunnan Yunnan , () is a landlocked province in the southwest of the People's Republic of China. The province spans approximately and has a population of 48.3 million (as of 2018). The capital of the province is Kunming. The province borders the ...

.Kew World Checklist of Selected Plant Families
/ref>

Ecology

The flowers of this species hardly open, because they are autogamous (self-pollinating). Before

anthesis Anthesis is the period during which a flower is fully open and functional. It may also refer to the onset of that period. The onset of anthesis is spectacular in some species. In ''Banksia'' species, for example, anthesis involves the extension ...

, the opening of the flower, the anther opens and the

pollinia A pollinium (plural pollinia) is a coherent mass of pollen grains in a plant that are the product of only one anther, but are transferred, during pollination, as a single unit. This is regularly seen in plants such as orchids and many species of mi ...

directly sink onto the stigmatic surface. Then pollen tubes start growing. This pollination mode enables the white helleborine to grow in deep shade, where the pollinators are almost absent. ''Cephalanthera damasonium'' has been indicated to be a mycorrhizal generalist. A 2017 investigation found that in Italy mycorrhizal associations are formed with

Agaricomycetes The Agaricomycetes are a class of fungi in the division Basidiomycota. The taxon is roughly identical to that defined for the Homobasidiomycetes (alternatively called holobasidiomycetes) by Hibbett & Thorn, with the inclusion of Auriculariales ...

Ascomycota Ascomycota is a phylum of the kingdom Fungi that, together with the Basidiomycota, forms the subkingdom Dikarya. Its members are commonly known as the sac fungi or ascomycetes. It is the largest phylum of Fungi, with over 64,000 species. The de ...

, ''Cadaphora luteo-olivacea'', ''Cenococcum geophilum'', ''Ceratobasidium'' including ''C. cornigerum'', ''Cryptococcus carnescens'', ''Exophiala salmonis'',

Hymenogastraceae The Hymenogastraceae is a family of fungi in the order Agaricales with both agaric and false- truffle shaped fruitbodies. Formerly, prior to molecular analyses, the family was restricted to the false-truffle genera. The mushroom genus ''Psilocy ...

including ''Hymenogaser cytrinus'' and ''H. bulliardii.'',

Pezizomycetes Pezizomycetes are a class of fungi within the division Ascomycota. Pezizomycetes are apothecial fungi, meaning that their spore-producing/releasing bodies ( ascoma) are typically disk-like, bearing on their upper surfaces a layer of cylindrical ...

, ''

Sebacina ''Sebacina'' is a genus of fungi in the family Sebacinaceae. Its species are mycorrhizal, forming a range of associations with trees and other plants. Basidiocarps (fruit bodies) are produced on soil and litter, sometimes partly encrusting stems ...

sp.'' and ''Tetracladium furcatum''. It has been suggested that the presence of this orchid species in a woodland is an indicator that edible

truffles A truffle is the fruiting body of a subterranean ascomycete fungus, predominantly one of the many species of the genus ''Tuber''. In addition to ''Tuber'', many other genera of fungi are classified as truffles including '' Geopora'', '' Pezi ...

can be found there, but this is not always the case.

Conservation

Globally, the conservation status of this species is vulnerable. In the United Kingdom this species is abundant but declining, and mainly a southern English species.

Etymology

'' Cephalanthera'' comes from the

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

κεφαλή ανθηρός, meaning "head flowering", thought to be a reference to the protruding position of the

anthers The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filam ...

. The species epithet ''damasonium'' also comes from

Ancient Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic p ...

and means 'I take away/diminish', possibly referring to a medical use for the plant. "Helleborine" may refer to deer using the orchid for food (many conservationists have noted that helleborine orchids are grazed by deer ). Alternatively it may denote that the plants are similar to

hellebores Commonly known as hellebores (), the Eurasian genus ''Helleborus'' consists of approximately 20 species of herbaceous or evergreen perennial flowering plants in the family Ranunculaceae, within which it gave its name to the tribe of Helleboreae. ...

(a group of species in the family

Ranunculaceae Ranunculaceae (buttercup or crowfoot family; Latin "little frog", from "frog") is a family of over 2,000 known species of flowering plants in 43 genera, distributed worldwide. The largest genera are '' Ranunculus'' (600 species), '' Delphiniu ...

). "Hellebore" comes from the Greek "álkē" and "bora", translating as "fawn" and "food of beasts".Dictionary.com
/ref>

References

Literature

* Claessens, J. & J. Kleynen: The flower of the European Orchid – Form and function, 2011. . * * {{Taxonbar, from=Q158126 damasonium Orchids of Europe Orchids of China Orchids of India Plants described in 1768