Biological Flora of the British Isles: Eryngium maritimum

Abstract

Summary1. This account presents information on all aspects of the biology of Eryngium maritimum L. (Sea Holly) that are relevant to understanding its ecological characteristics and behaviour. The main topics are presented within the standard framework of the Biological Flora of the British Isles: distribution, habitat, communities, responses to biotic factors, responses to environment, structure and physiology, phenology, floral and seed characters, herbivores and disease, history and conservation. 2. Eryngium maritimum is a native perennial hemicryptophyte, with a large taproot, spiny and leathery leaves and a pale bluish inflorescence. It has a more or less continuous distribution in suitable habitats along the coasts of Great Britain and Ireland up to about 55°N, but it is more scattered further north. On the west coast, it is found south of the Hebrides, and on the east coast, with some exceptions, south of Yorkshire. In Europe, it has a wide, but mainly southern temperate, European distribution along the coasts of the Atlantic Ocean, the Baltic, the Mediterranean, and the Black and Azov Seas. Its northern distribution limit is at c. 60°N. 3. Eryngium maritimum grows typically on sand and shingle beaches, foredunes and yellow dunes, as well as in semi-fixed grey dunes. Its habitats have full sunlight and are more or less dry. It occurs in many coastal plant communities from the beach inland, and because of its wide European distribution, it occurs with members of several different biogeographical species groups. 4. Protected from grazing by its spininess and sclerophylly, E. maritimum is nevertheless vulnerable to direct damage by trampling. It supports few insect herbivores, probably because of chemical defences. Historically, it has had a great number of medicinal uses. 5. Eryngium maritimum is unable to withstand competition from faster and more densely growing plant species. In many coastal regions, in both temperate and mediterranean parts of Europe, it is one of the rarest and most threatened plant species, mainly because of habitat loss and land-use changes.Key-words: climatic limitation, communities, conservation, ecophysiology, geographical and altitudinal distribution, germination, herbivory, mycorrhiza, reproductive biology, soils Sea Holly. Apiaceae subfamily Saniculoideae. A long-lived, perennial herb with a long, well-developed taproot and thick and fleshy rhizomes extending laterally from buried stems. Reproductive stems 0.15-0.60 m; lower part often root-like and buried in the sand; aerial part pale below but with bluish tinge above, erect, robust, terete or sulcate, glabrous, solid and widely branched above so that the plant forms an open cushion. Basal leaves several; lamina 4-10 9 15-20 cm, leathery, glabrous, intensely glaucous, subrotund in outline and palmately 3(À5) lobed; base truncate or cordate; venation palmate and reticulate, the veins thick, prominent; margin thick, cartilaginous, with large spinose teeth; petioles about as *Nomenclature of vascular plants follows Stace (2010) ...

Environmental filtering drives the shape and breadth of the seed germination niche in coastal plant communities

“…Most of the shifting dune species had low germination in all treatments, and may need some extra signal such as light quality, indicative of an adequately deep burial, as has been described in Glaucium flavum (Thanos et al, 1989) or Pancratium maritimum (Balestri and Cinelli, 2004). Low germination might, however, be a pattern as it has been reported in the shifting dune specialist Eryngium maritimum (Walmsley and Davy, 1997;Curle et al, 2004;Isermann and Rooney, 2014). The low germination of these species could be due to low seed quality rather than dormancy, but this should not affect our conclusions because we excluded from the analyses the species with < 40 % germination.…”

Natural persistence of the coastal plant Glehnia littoralis along temperate sandy coasts

“…Glehnia littoralis seeds can keep vigorous or turn more vigorous after seawater immersion, unlike most terrestrial plants 35 36 37 . This is a critical adaptation to seawater dispersal 33 38 39 . Supratidal zones are characterised by occasional seawater inundation 8 40 .…”

“…As a result, seeds of G. littoralis at supratidal zones can be inundated and dispersed 17 43 44 . They keep afloat for many days, like seeds of Eryngium maritimum, Cakile maritime and Canavalia rosea 17 38 39 . They are immersed in seawater, whereas await a chance to land at supratidal zones again 17 .…”

Biological Flora of the British Isles:Crambe maritima

“…The species frequency in the biogeographical regions of Black Sea, Mediterranean Sea, SW Atlantic and in the NW Atlantic‐S North Sea, SW Baltic were only 4% and at the NW Atlantic, North Sea, Baltic Sea and NW European. Atlantic and North Sea were 3% and only 1% at N North Sea and Baltic Sea (Isermann & Rooney ).…”