Woad

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Woad
Woad (Isatis tinctoria), fruiting

Woad ( Isatis tinctoria ), fruiting

Systematics
Rosids
Eurosiden II
Order : Cruciferous (Brassicales)
Family : Cruciferous vegetables (Brassicaceae)
Genre : Woad ( isatis )
Type : Woad
Scientific name
Isatis tinctoria
L.

The woad ( Isatis tinctoria ), Pastel or German Indigo is a biennial plant from the cruciferous family (Brassicaceae). It comes from West Asia , but was cultivated as a dye plant in Europe many centuries ago . Indigo (indigo blue) was extracted from the woad in Germany . The dye only oxidizes in air and slowly turns blue.

description

In the first year the biennial plant forms a leaf rosette with 20 to 30 cm long, lanceolate leaves with entire margins and a blue-green color. These are mostly bald, only those that are formed later are hairy. The woad usually reaches a size of 30 to 150 centimeters.

In the second year, upright stems up to 120 to 150 cm high grow, which are branched and bare at the top and covered with individual hairs at the bottom. The lowest leaves die off during flowering.

The woad blooms between May and July. The inflorescences consist of several umbels with yellow, rape-like flowers that connect to the stem end to a sweeping overall inflorescence. The individual flowers are without bracts, the four yellow petals have a diameter of 4 to 8 millimeters, are spatulate-tongue-shaped and rounded at the tip. There are also four yellowish-green, narrow, egg-shaped sepals. The ovary is club-shaped and flat. The bluish fruit is a pod 0.8 to 2 centimeters long and 3 to 7 millimeters wide with one or two oil-containing seeds each. It hangs on a 5 to 8 millimeter long stem that thickens towards the fruit set.

The number of chromosomes is 2n = 28.

  • Growth, general view

  • Stems with leaves

  • Inflorescences

  • Pods

  • Seeds

  • Plant parts in detail

ecology

The woad is a biennial half-rosette plant. Vegetative reproduction occurs through "root shoots". It has various adaptations to dry locations: The leaves are frosted blue by a thin wax coating and partly rolled over at the edge. The wax coating reduces the heat and lets the water roll off, which also prevents rot. In addition, the extensive root system is supplied with water through the centripetal water pipe in the center of the rosette.

From an ecological point of view, these are homogeneous "nectar-bearing disc flowers". The stamens are bent far outwards, which therefore usually causes cross- pollination . At the bottom of the six stamens there is a nectarium with a strong honey scent. Pollinators are different insects . The flowering period is between May and July.

The fruits are flattened, multi-seeded opening fruits and represent pods . The pods of the woad are reminiscent of winged nut fruits. In cruciferous vegetables, these opening capsule fruits consist of two carpels that form a frame (replum) inside the pod on which the seeds sit. Two seedless, sterile flaps (pericarp, valves) fall from this frame at the predetermined breaking points when the fruit is ripe and the seeds can fall out. In addition, it also spreads through humans. The fruit ripens between July and August.

distribution

The woad is originally found in Turkey, Algeria and Morocco and probably also in Europe. However, it was already cultivated in Europe in antiquity and is therefore considered an archaeophyte . The woad grows today mainly as a wild plant in Europe. He prefers dry slopes, rocks and dry ruderal spots . Regionally it is a character species of Echio-Melilotetum from the association Dauco-Melilotion, but in Central Europe it also occurs in societies of the association Convolvulo-Agropyrion or the classes Festuco-Brometea or Thlaspietea rotundifolii.

Systematics

The scientific name Isatis tinctoria was first published in 1753 by Carl von Linné in Species Plantarum .

The following subspecies are distinguished:

  • Isatis tinctoria subsp. tinctoria
  • Isatis tinctoria subsp. koelzii (Rech.f.) Jafri : plant and fruits are smaller than in Isatis tinctoria subsp. tinctoria : This subspecies occurs in Afghanistan and Pakistan.
  • Isatis tinctoria subsp. canescens (DC.) Malag. : It occurs in Italy, in the former Yugoslavia, in Bulgaria, Greece and in Algeria.

use

The woad stone in Sömmerda, was used to crush woad in the Middle Ages

The leaves contain the colorless glycoside indican , after harvest enzymatically in glucose and indoxyl cleaved and blue or bluish indigo oxidized is ( fermentation ). The complete conversion after a dyeing process takes several hours. The assertion that the expression blue-making is derived from this is only one of several unsecured assumptions (see the article Blue Monday ).

To obtain the dye, the leaf rosettes of the woad were harvested in its first year at the end of May and beginning of June. An orphan was used for this, with which the tuft of leaves was pushed off the root. That is why one spoke of the "stab" when it came to the woad harvest. After one prick the root sprout again and after about six weeks the next prick could take place. In a year that was favorable due to the weather, up to four harvests could be brought in. Most of the time, a higher number of stings was achieved after sowing winter woad, which germinated immediately after the snow melted and was ripe for the first sting earlier. After the stings in the first year, only some of the plants were allowed to complete their two-year cycle in order to obtain seeds from this woad. The rosettes of leaves of the pricked woad plants were taken to a running body of water to be washed, where the farmers pushed them under the water with rakes to clear the dirt of the field. Then they spread them out on meadows and let the leaves wither. Then they came under the wheel of the woad mill, which they crushed into woadmus. Fist-sized balls, the so-called woad balls, were formed from this mush. These were placed on racks to dry, where they shrank by about two thirds. This dried bale woad was then loaded onto carts and brought to the Waidmarkt, where the woad junkers examined it and made an offer to the farmers. It was not until the woad dealers that the semi-finished product was processed by breaking the balls on the woad floors and moistening them with water and urine. During the fermentation that followed, the above-described splitting of the indican took place. For the alkaline "potash" (essentially potassium carbonate ) required in the manufacturing process of the dye , "woad ash" was mostly made from beech wood or other hardwoods. Because of the wood protection effect (inhibited fungal growth), the blue paint obtained from woad is also suitable for painting doors, ceiling beams and church interiors, for example.

The woad bitter liqueur is made from the roots of the woad plant. In addition, woad root ( Isatidis Radix ) is used as a traditional Chinese remedy (Chinese name Banlangen ) to combat flu infections (but also measles and mumps ). Banlangen was in great demand, especially during the SARS epidemic in China, although an effect against viruses could not be proven.

history

The plant has been cultivated as a dye plant since ancient times . The Celts rubbed according Caesar ( De Bello Gallico ) before hostilities with woad ( vitrum ) a. Woad finds from the British Dragonby make it probable that the vitrum mentioned may have been woad. “All Britons, on the other hand, turn themselves blue-green with woad, which makes them look all the more terrible in battle; they also have long hair ... ”The dominant color of the Middle Ages was probably the color of woad: blue-violet. Woad was important for the production of blue linen until the 16th century . It was then supplanted by the real indigo from the tropical butterfly family Indigofera tinctoria , which originally came from India but was mainly grown in the American colonies. With the commercial production of synthetic indigo since 1897, natural indigo also disappeared from the market.

Nowadays, woad has a certain meaning again as an ecological color. In some places today, fabrics are again dyed with 'Erfurt Blue'. After the fall of the Berlin Wall , there was particularly strong demand in Thuringia for the blue paint made from woad for the faithful restoration of churches and other buildings.

Woad cultivation in Thuringia

In Germany, woad has been grown mainly in Thuringia since the 9th century . As the center of the woad trade, the city ​​of Erfurt gained power and wealth, as did the other woad cities . Waidmühlen were required for processing . In Thuringia, including in the horse life area , woad was grown in fallow fields on around 50 acres (around 11.5 hectares). This broke the three-field economy introduced by Charlemagne . The sowing took place in the pre- and post-Christmas period on the snow in broad sowing . With increasing improvement in care conditions, row sowing was carried out to optimize the use of seeds . This involved sowing ½ Erfurter Metze (about 14.9 l) of seeds on an area of ​​1 Gotha field (about 2270 m²) . With the sprouting of the plants, the arduous weed control began with the use of many workers. At harvest time, the farmers and their numerous assistants, such as migrant workers from Lusatia , slid on their knees from plant to plant and cut off the leaf rosette, which was as close as possible to the roots, with the chisel-like waffle iron. The process was repeated three to four times a year. Then the woad leaves were washed, dried and brought to the woad mill. There the vertical mill wheel, often made of Seeberg sandstone , was turned in a circle by draft animals, whereby the plants in the mill pan were crushed. The resulting pasty mass was then beaten firmly on piles and protected from the weather dishes of the barns a day were left. The plants began to decompose in a fermentation process that led to chemical conversion. Women and children now formed dumplings the size of a fist out of the porridge, the size of which depended on the applicable law. The dumplings were dried on trays that were shoved into covered logs . After two to three sunny days of drying, the woad was carted to the prescribed market. B. from horse life to Gotha , later to (Bad) Langensalza and Erfurt. It was not allowed to be stored in the villages. However, the cultivation and processing of woad into indigo were not without problems. In times of great famine, woad cultivation used up large areas of arable land. With the fermentation and dyeing processes, the trade caused a terrible stench and the wastewater was heavily polluted. The aesthetic added value of blue clothing obviously outweighed these disadvantages. In the wake of the Thirty Years' War and due to competition from the cheaply imported indigo, woad cultivation gradually lost its importance. At the beginning of the 20th century, the last wood mill in horse life stopped working. Since 1997, woad has been grown again by a small manufacturer in the area around Erfurt and marketed as Erfurt blue .

Growing of woad in the Lauragais

The area southeast of Toulouse, the Lauragais , has been one of the main areas where woad is grown in Europe since the late Middle Ages. Many farmers in the region gave up normal agriculture and made good profits from cultivating the inedible plant, which, however, quickly disappeared as a result of the import of indigo dyes from the overseas colonies ( Louisiana etc.) in the 17th and 18th centuries, so that one had to turn back to traditional farming. The area of ​​the Lauragais has since been nicknamed pays de cocagne - in German about land of milk and honey , where cocagne also refers to the bale into which the leaves of the woad were compressed for storage or transport.

swell

literature

  • F. Fischer: The blue wonder of woad. Rediscovery of an old useful and cultivated plant. vgs, Cologne 1997, ISBN 3-8025-1333-9 .
  • Rolf Gelius: On the history of the European woad indigo. In: NTM 17, 1980, pp. 65-83.
  • Dietmar Aichele, Heinz-Werner Schwegler: The flowering plants of Central Europe. Volume 3: Evening primrose plants to reddish plants . Franckh-Kosmos, Stuttgart 1995, ISBN 3-440-06193-0 , p. 290 .
  • KU Heyland, H. Hanus, ER Keller: Handbuch des Pflanzenbaues. Volume 4. Oil fruits, fiber plants, medicinal plants and special crops. Eugen Ulmer, Stuttgart 2006, ISBN 3-8001-3203-6 , pp. 527-531.
  • Fritz Lauterbach: History of the dyes used in Germany in dyeing with special consideration of medieval woad construction. Veit, Leipzig 1905.
  • Hansjürgen Müllerott: Sources on woad cultivation in Thuringia: with an excursus into the other woad cultivation areas in Europe and the Middle East; Industrial archeology, historical geography, field naming, ancient history, settlement and territorial history, archaeobotany, botany. Thuringian Chronicle Publ. Müllerott, Arnstadt, 1993, ISBN 3-910132-12-X .
  • Henricus Crolachius: Isatis herba or the woad plant: understandable description of the culture of the woad plant, which is usually called guado, whose cultivation is widespread in Thuringia and its preparation as a dye to dye the wool blue. Hans Jakob Geßner, Zurich 1563, Thüringer Chronik-Verl. Müllerott, Arnstadt 1991 (facsimile print), ISBN 3-910132-99-5 .
  • Martin Baumann, Steffen Raßloff (eds.): City of flowers Erfurt. Waid - Gartenbau - iga / egapark ( publications of the association for the history and antiquity of Erfurt . Vol. 8). Erfurt 2011. ISBN 978-3-86680-812-6 .
  • Horst Benneckenstein: Waidstadt Erfurt. Progress, Erfurt 1991, ISBN 3-13368-068-4 .
  • Renate Kaiser-Alexnat: wonder being woad . Experiences about people and plants - especially woad - told in pictures and stories. epubli, Berlin 2012, ISBN 978-3-8442-1898-5
  • Ruprecht Düll , Herfried Kutzelnigg : Pocket dictionary of plants in Germany and neighboring countries. The most common Central European species in portrait . 7th, corrected and enlarged edition. Quelle & Meyer, Wiebelsheim 2011, ISBN 978-3-494-01424-1 .
  • Frank Boblenz : Yellow flowers and blue color - for woad cultivation in the Erfurt countryside in the 16th century. In: Home Thuringia. Volume 21, No. 1-2, 2014, ISSN  0946-4697 , pp. 46-48.
  • Georg Schwedt : Woad - blue gold from Thuringia. Verlag Rockstuhl, Bad Langensalza 2017, ISBN 978-3-95966-169-0 .
  • Paul Zschiesche: Erfurt hunting and hunting. Verlag Rockstuhl, Bad Langensalza 2017 (reprint from 1896), ISBN 978-3-95966-272-7 .

Individual evidence

  1. ↑ a b Erich Oberdorfer : Plant-sociological excursion flora for Germany and neighboring areas . 8th edition. Verlag Eugen Ulmer, Stuttgart 2001, ISBN 3-8001-3131-5 . Page 446.
  2. ^ A b Isatis in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program. National Germplasm Resources Laboratory, Beltsville, Maryland. Retrieved July 27, 2017.
  3. ↑ Carl von Linné: Species Plantarum. Volume 2, Lars Salvius, Stockholm 1753, p. 670 ( digitized versionhttp: //vorlage_digitalisat.test/1%3Dhttp%3A%2F%2Fwww.biodiversitylibrary.org%2Fopenurl%3Fpid%3Dtitle%3A669%26volume%3D2%26issue%3D%26spage%3D670%26date%3D1753~GB%3D~ IA% 3D ~ MDZ% 3D% 0A ~ SZ% 3D ~ double-sided% 3D ~ LT% 3D ~ PUR% 3D ).
  4. ^ Meyer's Large Conversational Lexicon. Volume 10, Leipzig 1907, p. 41 Keyword “Isatis” .
  5. ↑ Inge-Marie Peters: Ashes. In: Lexikon des Mittelalters , Volume 1, p. 1102
  6. ^ Jörg Mildenberger: Anton Trutmann's ›Pharmacopoeia‹, Part II: Dictionary. , Königshausen & Neumann, Würzburg 1997 (= Würzburg medical-historical research , 56), p. 2265 f.
  7. ↑ Caesar: De bello Gallico. Liber V 14, 2. ( Commentarii de bello Gallico ).
  8. ^ M. Van der Veen, AR Hall, J. May: Woad and the Britons Painted Blue. In: Oxford Journal of Archeology. Volume 12, No. 3, 1993, pp. 367-371, DOI: 10.1111 / j.1468-0092.1993.tb00340.x .
  9. ↑ www.gottwein.de
  10. ↑ Harald Paland: Blue - Isatis, the Madonna, Aniline, the sky and blue jeans. In: Practice of the natural sciences - chemistry in school. Volume 60, No. 6, 2011, pp. 26-29, Aulis Verlag 2011
  11. ^ Erfurt & Waid - Erfurt blue. Retrieved April 27, 2019 (German).

Web links

Commons : Woad ( Isatis tinctoria )  - album with pictures, videos and audio files
Wiktionary: Woad  - explanations of meanings, word origins, synonyms, translations