''Silaum silaus'', commonly known as pepper-saxifrage, is a

perennial In horticulture, the term perennial ('' per-'' + '' -ennial'', "through the year") is used to differentiate a plant from shorter-lived annuals and biennials. It has thus been defined as a plant that lives more than 2 years. The term is also ...

plant in the family Apiaceae (Umbelliferae) (the carrot family) found across south-eastern, central, and western Europe, including the British Isles. It grows in damp grasslands on neutral soils.

Description

''Silaum silaus'' is an erect,

glabrous Glabrousness () is the technical term for a lack of hair, down, setae, trichomes, or other such covering. A glabrous surface may be a natural characteristic of all or part of a plant or animal, or be due to loss because of a physical condition, ...

umbellifer Apiaceae () or Umbelliferae is a family of mostly aromatic flowering plants named after the type genus '' Apium,'' and commonly known as the celery, carrot, or parsley family, or simply as umbellifers. It is the 16th-largest family of flowering ...

with woody, stout and cylindrical tap roots, which are hot and

aromatic In organic chemistry, aromaticity is a chemical property describing the way in which a conjugated system, conjugated ring of unsaturated bonds, lone pairs, or empty orbitals exhibits a stabilization stronger than would be expected from conjugati ...

. ''S. silaus'' has dark grey or black petioles at the top; petiole remains are found at the bottom of the stem, which is solid and striate. Its umbels are 2–6 cm in diameter, are terminal or axillary, and compound, with 4 to 15 angled rays of 1–3 cm; the peduncle is larger than the rays, and both are papillose. The flowers are mostly

hermaphroditic A hermaphrodite () is a sexually reproducing organism that produces both male and female gametes. Animal species in which individuals are either male or female are gonochoric, which is the opposite of hermaphroditic. The individuals of many ...

. ''Silaum silaus'' has 2–4-

pinnate Pinnation (also called pennation) is the arrangement of feather-like or multi-divided features arising from both sides of a common axis. Pinnation occurs in biological morphology, in crystals, such as some forms of ice or metal crystals, and ...

leaves, which have a triangular and

lanceolate The following terms are used to describe leaf plant morphology, morphology in the description and taxonomy (biology), taxonomy of plants. Leaves may be simple (that is, the leaf blade or 'lamina' is undivided) or compound (that is, the leaf blade ...

outline, a long petiole and the primary divisions are long-stalked. Segments are 10–15 mm long, shaped from lanceolate to linear, the ends are

acuminate The following terms are used to describe leaf plant morphology, morphology in the description and taxonomy (biology), taxonomy of plants. Leaves may be simple (that is, the leaf blade or 'lamina' is undivided) or compound (that is, the leaf blade ...

or obtuse and mucronate, the leaves are finely serrulate, with a prominent

midrib A primary vein, also known as the midrib, is the main vascular structure running through the center of a leaf. The primary vein is crucial for the leaf’s efficiency in photosynthesis and overall health, as it ensures the proper flow of material ...

; the apex is often reddish in colour. There are 1-

upper

cauline A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, fl ...

leaves present, which are either simple or reduced to a sheath; there is no petiole and the

cotyledons A cotyledon ( ; ; "a cavity, small cup, any cup-shaped hollow", gen. (), ) is a "seed leaf" – a significant part of the embryo within the seed of a plant – and is formally defined as "the embryonic leaf in seed-bearing plants, one or mor ...

are tapered at the base. There are 0–3

bracts In botany, a bract is a modified or specialized leaf, associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are usually different from foliage leaves in size, color, shape or texture. They also loo ...

and 5–11 bracteoles; the

pedicels In botany, a pedicel is a stem that attaches a single flower to the inflorescence In botany, an inflorescence is a group or cluster of flowers arranged on a plant's Plant stem, stem that is composed of a main branch or a system of branch ...

are linear-lanceolate with scarious margins. The flowers are yellowish and 1.5 mm across, with absent

sepals A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 Etymology The term ''sepalum'' ...

, and the styles form a stylopodium. The fruits are 4–5 mm in size, oblong-ovoid, and are rarely compressed. The

commissure A commissure () is the location at which two objects wikt:abut#Verb, abut or are joined. The term is used especially in the fields of anatomy and biology. * The most common usage of the term refers to the brain's commissures, of which there are at ...

is broad, the mericarps are prominent with slender ridges and lateral forming narrow wings; a carpophore is present. There are numerous vittae, with stout

of 2–3 mm in size, and the stigmas are capitate.

Taxonomy

''Silaum silaus'' was one of the many species described by

Carl Linnaeus Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming o ...

in volume 1 of the 1753 edition of his ' as ''Peucedanum silaus''. It was given its current binomial name in 1915 by Swiss botanists Hans Schinz and Albert Thellung in 1915. The

etymology Etymology ( ) is the study of the origin and evolution of words—including their constituent units of sound and meaning—across time. In the 21st century a subfield within linguistics, etymology has become a more rigorously scientific study. ...

of the genus name ''Silaum ''is uncertain, although it may refer to the mountainous plateau La Sila in southern

Italy Italy, officially the Italian Republic, is a country in Southern Europe, Southern and Western Europe, Western Europe. It consists of Italian Peninsula, a peninsula that extends into the Mediterranean Sea, with the Alps on its northern land b ...

. Another possible explanation is that ''Silaum'' may be derived from the yellow

ochre Ochre ( ; , ), iron ochre, or ocher in American English, is a natural clay earth pigment, a mixture of ferric oxide and varying amounts of clay and sand. It ranges in colour from yellow to deep orange or brown. It is also the name of the colou ...

, related to the colour of the plant's flowers. ''Silaus'' is an old generic name used by Pliny. ''Silaum silaus'' bears the common name pepper-saxifrage (with or without hyphenation) despite being neither a

saxifrage ''Saxifraga'' is the largest genus in the family Saxifragaceae, containing about 473 species of holarctic perennial plants, known as saxifrages or rockfoils. The Latin word ''saxifraga'' means literally "stone-breaker", from Latin ' ("rock" or " ...

nor peppery in taste.

Distribution and habitat

''Silaum silaus'' is found in western, central and south-eastern

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

(including

Great Britain Great Britain is an island in the North Atlantic Ocean off the north-west coast of continental Europe, consisting of the countries England, Scotland, and Wales. With an area of , it is the largest of the British Isles, the List of European ...

), north to the

Netherlands , Terminology of the Low Countries, informally Holland, is a country in Northwestern Europe, with Caribbean Netherlands, overseas territories in the Caribbean. It is the largest of the four constituent countries of the Kingdom of the Nether ...

and

Sweden Sweden, formally the Kingdom of Sweden, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. It borders Norway to the west and north, and Finland to the east. At , Sweden is the largest Nordic count ...

but is absent from

Portugal Portugal, officially the Portuguese Republic, is a country on the Iberian Peninsula in Southwestern Europe. Featuring Cabo da Roca, the westernmost point in continental Europe, Portugal borders Spain to its north and east, with which it share ...

. In Great Britain, it is found mainly south of the far south of

Scotland Scotland is a Countries of the United Kingdom, country that is part of the United Kingdom. It contains nearly one-third of the United Kingdom's land area, consisting of the northern part of the island of Great Britain and more than 790 adjac ...

. The species is listed as an

invasive species An invasive species is an introduced species that harms its new environment. Invasive species adversely affect habitats and bioregions, causing ecological, environmental, and/or economic damage. The term can also be used for native spec ...

Denmark Denmark is a Nordic countries, Nordic country in Northern Europe. It is the metropole and most populous constituent of the Kingdom of Denmark,, . also known as the Danish Realm, a constitutionally unitary state that includes the Autonomous a ...

. ''Silaum silaus'' grows in a wide variety of habitats, generally preferring those with damper soils. Specifically, ''S. silaus'' can be found in unimproved neutral grassland, railway and road verges and

meadows A meadow ( ) is an open habitat or field, vegetated by grasses, herbs, and other non-woody plants. Trees or shrubs may sparsely populate meadows, as long as they maintain an open character. Meadows can occur naturally under favourable condition ...

(hay, water and lowland meadows); it is also occasionally found on chalk downs and vegetated shingle.

Ecology

''Silaum silaus'' is an indicator of agriculturally unimproved meadows, and is part of a group (in the

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Northwestern Europe, off the coast of European mainland, the continental mainland. It comprises England, Scotlan ...

) of flowering plants specially associated with neutral grassland associated with low-nutrient regimes. This group is declining in the UK due to agricultural improvement, diffuse pollution and

habitat fragmentation Habitat fragmentation describes the emergence of discontinuities (fragmentation) in an organism's preferred environment (habitat), causing population fragmentation and ecosystem decay. Causes of habitat fragmentation include geological proces ...

and hence ''S. silaus'' is on the

United Kingdom Biodiversity Action Plan The United Kingdom Biodiversity Action Plan (UK BAP) was the UK government's response to the Convention on Biological Diversity, opened for signature at the Rio Earth Summit in 1992. The UK was the first country to produce a national Biodiversi ...

. At least three species of

moth Moths are a group of insects that includes all members of the order Lepidoptera that are not Butterfly, butterflies. They were previously classified as suborder Heterocera, but the group is Paraphyly, paraphyletic with respect to butterflies (s ...

larvae A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect developmental biology, development such as insects, some arachnids, amphibians, or cnidarians typical ...

in the UK use the plant as a food source – '' Sitochroa palealis'', '' Agonopterix ciliella'' and '' Agonopterix yeatiana''. ''Silaum silaus'' fruit has been identified from substage III of the Hoxnian interglacial period (a stage in the middle

Pleistocene The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...

) in the British Isles.

Uses

''Silaum silaus'' is listed in John Parkinson's 1640 work ''Theatrum Botanicum'' as being able to soothe "frets" in infants.

References

External links

* {{Taxonbar, from=Q1520956 Flora of Europe Plants described in 1753 Taxa named by Carl Linnaeus silaus