Eryngium maritimum

''Eryngium maritimum'', the sea holly or sea eryngo, or sea eryngium, is a perennial species of flowering plant in the family Apiaceae and native to most European coastlines. It resembles a thistle in appearance because of its burr-shaped inflorescences. Despite its common name, it is not a true holly but an umbellifer.

Etymology

''E. maritimum'' was formally described by Linnaeus in his Species Plantarum I: 233 (1753). The generic name ''Eryngium'' derives from Greek and may have developed from a description of the plant by Theophrastus (300 BC), who referred to it as "Eryngion", meaning a spiny plant. Alternatively, the name may have derived from the Greek word "eruggarein", meaning to eructate (belch), since the plant was used to treat various digestive disorders such as trapped gases.

The specific epithet ''maritimum'' means "of the sea".

The common English name appears to date from the 16th century. In his 1548 publication ''The Names of Herbes'', the naturalist William Turner stated that "Eryngium is named in englishe sea Hulver or sea Holly".

Taxonomy

Although hybrids of ''E. maritimum'' have been reported, they are relatively few. For example, records have been made of a hybrid between ''E. maritimum'' and '' E. campestre'' (=''Eryngium'' x ''rocheri'' Corb. ex Guétrot) in France, and in the region of Valencia, Spain.

The species' chromosome number is 2n = 16.Tutin TG. 1980. ''Umbellifers of the British Isles''. Botanical Society of the British Isles Handbook No. 2, London. .

Description

Sea holly is a glabrous, intensely glaucous, clump-forming perennial that typically reaches a height of approximately 60 cm. It is a succulent xerophyte with a deep, well-developed root system and waxy leaf cuticle. The leaves are stiff, spiny, and leathery in texture. The basal leaves, which measure 5 – 15 cm in length and are rolled when young,Poland J, Clement EJ. 2009. ''The Vegetative Key to the British Flora''. Botanical Society of Britain and Ireland. are palmately 3-lobed and suborbicular, truncate, or cordate at the base. The stem leaves are similar, but are smaller, sessile, and palmate. All leaves are characterised by thick margins, often with purplish veins, and the presence of stomata on both sides. The petiole is channelled and dilated at the base.

The cotyledons are abruptly contracted into a petiole.

The flowers are bluish white and measure 8mm across, in 1.5 – 2.5 cm heads The bracts are spiny, and the bracteoles are longer than the flowers. The sepals measure 4 – 5 mm and are longer than the petals.

The flowers are attractive to butterflies. It flowers June to September.

The fruit is 13 – 15 mm, more or less uncompressed and covered in stigmatic papillae which become longer towards the apex. The styles are about 6 mm long, divergent to somewhat recurved.

Identification

Apart from the context of its specific coastal habitat, sea holly may also be distinguished from its congeners by the deeper, strongly spiny teeth on the basal leaves and stem leaves.

Distribution

Throughout its range, sea holly is a coastal species, occurring locally and almost continuously along the coastlines of England and Ireland. In Great Britain, it is most abundant on the south and west coasts. However, it has largely become extinct from the coasts of northeast England and Scotland. Nevertheless, it may have once been more common and widespread there.Isermann M, Rooney P. 2014. Biological Flora of the British Isles: ''Eryngium maritimum''. ''Journal of Ecology'' 102: 789 – 821. It was formerly extant in Shetland, but it never properly established itself at the northernmost limit of its native range. The last documented occurrence in Shetland was at Fitful Head in 1884, where the plant is presumed to have been widespread on the sands of the Bay of Quendale.

In Europe and adjacent parts of northern Africa and the Middle East, the plant has a wide native distribution. In these regions, it occurs on the shores of the Atlantic Ocean, the Baltic and Mediterranean Seas as well as the Black and Azov Seas. The distribution also extends northwards into Denmark, Germany, Poland, Lithuania, Latvia, and Estonia, along the Skagerrak and the Swedish islands of Gotland and Öland. The Scandinavian distribution is relatively southerly, extending only as far north as southern Norway and Sweden.

Sea holly has been introduced to parts of eastern North America, where it was once valued as an ornamental plant for coastal restoration. It has also been introduced to Australia with the planting of marram grass.

Habitat and ecology

Sea holly grows characteristically on the well-drained substrates of sand dunes and shingles, and is restricted to regions with mild winters. More rarely, it can be found growing on rocky coasts with patches of sand interspersed between artificial hard coastal protection features with a similar structure to shingle. In northern Britain, its distribution is limited by the lack of suitable dune systems on which to grow It withstands the harsh environmental conditions typical of beaches and coastal dune habitats worldwide; namely low soil nutrient levels, frost, strong salty winds, high temperatures and insolation, and periodic sand burial.

Sea holly is associated with various shingle and strandline communities, where it may be scattered within the vegetation. On shingles, sea holly occurs within Honckenya peploides-Cakile maritima strandline community above the tidal limit Rodwell JS (ed.). 2000. ''British Plant Communities. Vol. 5. Maritime Communities and Vegetation of Open Habitats''. Cambridge University Press, Cambridge, UK On dunes, sea holly may be found growing in the Elymus farctus ssp. boreali-atlanticus foredune community, the pioneer vegetation on foredunes, with ''Elytrigia juncea'' (E. farctus) as a dominant species.

Sea holly is a poor ecological competitor that generally thrives in open areas, declining when habitats are invaded by shrubby species such as ''Rosa rugosa'', ''Hippophae rhamnoides'', ''Elaeagnus commutata'' and '' Salix repens'' due to substantial shading effects This is because sea holly is a light-demanding plant, although it is protected against water stress through excessive insolation thanks to its succulent equifacial leaves.

Sea holly has deep, well-developed taproots for water storage, allowing the plant to survive long dry periods that may occur in its habitat. The root system also shows a high degree of plasticity in response to the dynamics of coastal ecosystems and may consequently develop a rhizome-like structure. For example, in response to permanent sand burial, the root internodes gradually lengthen in such a way that the perennating buds are brought closer to the ground surface for ensuring the plants' survival throughout the growing seasons.

Status

Despite a widespread native European distribution, populations of this species have declined significantly in the northern parts of its range, with some of these already having become extinct. It is now threatened or endangered in most European countries and included in endangered plant lists and Red Data Books of several of these countries In Britain, its historic decline may be at least partly attributable to being dug up from the wild on account of its popularity as an ornamental plant in gardens on dry soils.

In culture, use and relationship with humans

Like other species in the genus, ''E. maritimum'' has been traditionally consumed to combat various ailments, especially thanks to the plant's high antioxidant activity and content of phenolic and flavonoid compounds. It has been utilised for its diuretic, stimulant, cystotonic, stone inhibitor, aphrodisiac, expectorant and anthelmintic properties. Moreover, essential oils, extracted by hydro-distillation, from the aerial parts of the plant have been found to contain oxygenated sesquiterpenes with antimicrobial activity against ''E. coli'' and '' L. monocytogenes''.

The roots of ''E. maritimum'' were formerly candied as a sweetmeat and recommended by Dioscorides as a remedy for flatulence. The young shoots may also be eaten like asparagus.

Sea holly has often been represented in paintings and other artwork, such as in works by Irish artist Patrick O'Hara and on postage stamp prints such as the 1967 one-franc stamp in Belgium, and the 25-pfennig stamp in Germany The plant has also been mentioned in various plays and poems, most notably in the Merry Wives of Windsor by Shakespeare and in the Italian Journey by Goethe.

They are named in a speech by Falstaff:

Sea holly was nominated the 2002 County flower for the city of Liverpool.Plantlife. Sea Holly. Available at https://www.plantlife.org.uk/uk/discover-wild-plants-nature/plant-fungi-species/sea-holly (accessed 03/10/2022) Asteroid 199194 Calcatreppola was named after this plant. The official was published by the Minor Planet Center on 25 September 2018 ().

Gallery

File:Eryngium maritimum Mikołajek nadmorski RB1.jpg, On the shore of the Mediterranean Sea near the mouth of Dalyan River, Turkey
File:Eryngium maritimum 1.jpg, Whole plant, Meia Praia beach, Lagos, Portugal
File:Eryngium maritimum 2.jpg, Flowers, Meia Praia beach, Lagos, Portugal
File:Eryngium maritimum - Mikolajek nadmorski R51 ubt.jpg, In Rewa, Poland
File:Eryngium maritimum-01 (xndr).jpg, Close-up of inflorescence
File:Eryngium maritimum MHNT.BOT.2008.1.8.jpg, MHNT botanical specimen
File:Eryngium maritimum 2-Αγγελοχώρι.jpg, In Aggelohori, Greece

References

External links

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Plants for a Future—PFAF Plant Database: ''Eryngium maritimum'' (Sea Holly)

Schutzstation-wattenmeer.de: Further information and images
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Linnaeus.nrm.se; Den virtuelle floran: ''Distribution map''

{{Taxonbar, from=Q21110

maritimum
Flora of Europe
Flora of Lebanon
Flora of Ukraine
Medicinal plants of Europe
Plants described in 1753
Taxa named by Carl Linnaeus