Unité de Malherbologie & Agronomie
Weed Science & Agronomy
|THE SPECIES||THE DATA||THE CONTRIBUTORS|
THE WEED SPECIES
The knowledge base includes the description of 580 species of annual and perennial weed species excluding permanent grassland, flower crops, nurseries and crops under glass. The shoots of cultivated plants and young trees and bushes are not considered.
The list of weeds was established by German, English, Belgian, Spanish, French, Italian and Portuguese experts for their countries and for Denmark, Luxembourg and the Netherlands. The experts considered the species as common, rare, or not found on the territory of each country considered.
For France and some other countries, as well as common and/or widespread species, depending on the area, species which are rare (Lolium temu/entum, Nigella damascena or Agrostemma githago), which are very common locally (Phalaris paradoxe, Chamaemelum fuscatum) or which, although introduced recently, are multiplying and spreading rapidly (Dichanthium saccharoides, Senecio inaequidens...) have been listed.
The files describing the species contain the following information:
Scientific name: The name given in the software is generally that adopted to designate a species, taking accourt of the edited nomenclature rules in the International Botanical Nomenclature Code (For France, see the Index Synonymique de la Flore de France de Michel Kerguélen - 1999).
A species is defined via 2 terms; the first is the genus name, the second that of the species, followed by the author's name and its description; if there is a third term, division of the species, it is that of its subspecies (subsp.) or the variety (var.). In this database, the authors' names are not abridged apart from Linnaeus which becomes L..
Synonyms of the scientific name: This heading has the synonyme used in the most current works and flora; it allows a more "open" consultation of information.
Common name: This is one of the common names most widely used for the species; the common name is given in the other languages (6 software languages plus Danish and Dutch).
Synonyms of the common name: This heading mentions other common or vernacular names. For Spain the Catalan (cat.) name is given.
Code: The weed computer code is taken from BAYER AG - Important Crops of the World and their Weeds 2nd edition (1992).
This is a 5 letter code. Generally the first 3 correspond to the first letters of the genus name and the following 2 to the species name (or to one of its synonyme). When a plant cannot be found in the reference work, a provisional code is given in brackets.
The description characters are concise and homogeneous; they concern the shape of the cotyledons and the first leaves for the dicotyledons; preleafing and the shape of the ocrea, the leaf length/width ratio, the hairiness, the presence of a ligule or auricle for gramineous plants.
The adult plant:
The characteristics of morphological description concern the height and bearing of the plant and the characteristics of the stem, leaves, flowers and fruits. .
The current importance in crops and the existence of populations which are resistant to some herbicides are indicated.
Indications on medical, food and industriel properties and uses of different species are generally taken from "La Flore Complète Illustrée" in colour by Bonnier and Douin, "They must be viewed with the eye of the science historien or the chemist but certainly not with that of the consumer or person who is prescribing for himselft'.
Information on protection of species considered rare regionally or nationally for France come from the Fauna and Flora Secretariat of the National Natural History Museum.
Risk of confusion: this heading is not systematically filled in for the young plant, vegetative or adult plant stages. The species mentioned are limited in the list to those which can be found and confused in the same situation (simultaneous presence in space and time).
Biological type: This corresponds to the information contained in the flora and is limited to general terms (annuel, perennial, perennial with tubers, etc.).
The ecological information on species was processed separately for each of the ten countries starting from the references and the experience in the field of the experts consulted. Some indications are not precise, especially for rare species. Uncertainty on ecological affinity or distribution for certain species is taken into account by the software.
The ecogeographical characteristics considered are : climate regions, type of crop, soil reaction (pH) and soil texture.
Database and translation:
Scientific Co-ordination: J.
Gasquez and J. P. Lonchamp
Information editing: J. P. Lonchamp