''Draba aizoides'' is a species of flowering plant in the family

Brassicaceae Brassicaceae () or (the older) Cruciferae () is a medium-sized and economically important family of flowering plants commonly known as the mustards, the crucifers, or the cabbage family. Most are herbaceous plants, while some are shrubs. The leav ...

, known as yellow whitlow-grass. It is native to Europe where it is found on

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms w ...

rocks and walls. In the British Isles it is found only on the

Gower Peninsula Gower ( cy, Gŵyr) or the Gower Peninsula () in southwest Wales, projects towards the Bristol Channel. It is the most westerly part of the historic county of Glamorgan. In 1956, the majority of Gower became the first area in the United Kingdom ...

in Wales.

Description

''Draba aizoides'' is a

perennial plant A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also wide ...

, with a basal rosette of linear, stiff, entire leaves fringed with white bristles. The erect hairless and leafless stems grow to , or exceptionally to , and carry a small number of yellow flowers. These have four broad, hardly-notched petals and four hairless sepals. The seed pods are elliptical. The plant flowers in March and April in the British Isles.

Distribution and habitat

''Draba aizoides'' has a wide distribution in the mountains of southern and central Europe, from the

Pyrenees The Pyrenees (; es, Pirineos ; french: Pyrénées ; ca, Pirineu ; eu, Pirinioak ; oc, Pirenèus ; an, Pirineus) is a mountain range straddling the border of France and Spain. It extends nearly from its union with the Cantabrian Mountains to ...

in the west, through the

Alps The Alps () ; german: Alpen ; it, Alpi ; rm, Alps ; sl, Alpe . are the highest and most extensive mountain range system that lies entirely in Europe, stretching approximately across seven Alpine countries (from west to east): France, Sw ...

to the

Carpathians The Carpathian Mountains or Carpathians () are a range of mountains forming an arc across Central Europe. Roughly long, it is the third-longest European mountain range after the Urals at and the Scandinavian Mountains at . The range stretche ...

. It also has a number of isolated occurrences, including the

Vosges The Vosges ( , ; german: Vogesen ; Franconian and gsw, Vogese) are a range of low mountains in Eastern France, near its border with Germany. Together with the Palatine Forest to the north on the German side of the border, they form a singl ...

, Jura,

Cévennes The Cévennes ( , ; oc, Cevenas) is a cultural region and range of mountains in south-central France, on the south-east edge of the Massif Central. It covers parts of the ''départements'' of Ardèche, Gard, Hérault and Lozère. Rich in geogra ...

Auvergne Auvergne (; ; oc, label= Occitan, Auvèrnhe or ) is a former administrative region in central France, comprising the four departments of Allier, Puy-de-Dôme, Cantal and Haute-Loire. Since 1 January 2016, it has been part of the new region Au ...

Côte d'Or Côte is a British cafe chain founded by Richard Caring, Andy Bassadone, Chris Benians and Nick Fiddler in Wimbledon, London Wimbledon () is a district and town of Southwest London, England, southwest of the centre of London at Charing Cros ...

, Plateau de Langres and the Belgian

Ardennes The Ardennes (french: Ardenne ; nl, Ardennen ; german: Ardennen; wa, Årdene ; lb, Ardennen ), also known as the Ardennes Forest or Forest of Ardennes, is a region of extensive forests, rough terrain, rolling hills and ridges primarily in Be ...

. In the

British Isles The British Isles are a group of islands in the North Atlantic Ocean off the north-western coast of continental Europe, consisting of the islands of Great Britain, Ireland, the Isle of Man, the Inner and Outer Hebrides, the Northern Isl ...

, it is found only on limestone cliffs on the

, from

Worm's Head Worm's Head ( cy, Ynys Weryn) is a headland, at Rhossili, part of the City and County of Swansea Swansea (; cy, Abertawe ) is a coastal city and the second-largest city of Wales. It forms a principal area, officially known as the City ...

to Pwlldu Head. It is a lowland species and grows in pockets of soil in damp cracks and crevices in limestone rocks. When it occurs in grassland or in bare soil away from limestone rocks it seldom thrives.

Status in Britain

This plant was first discovered in 1795 in the British Isles, and genetic analysis has shown that the populations in the Gower are quite distinct from those growing in continental Europe, so the plant does seem to be native to Britain. Although its total population is very small, its overall distribution has largely remained stable; plant collectors have removed some plants but the less accessible ones are persisting, although in some sites they have decreased somewhat for reasons that are not clear.

References

External links

* {{Taxonbar, from=Q159598 aizoides Flora of Europe Gower Peninsula Plants described in 1767