Field descriptors are a group of data items which have been obtained by direct observation at the collection site. In larger units, such data are often recorded in the body text of the label (attribute field description text).
Diagram 12: Local ethnobotanical information as example for a field descriptor subtype definition
CDEFD initially attempted to develop a set of descriptors for plants. However, even in this restricted case the type and number of descriptors recorded separately may vary greatly between collectors and according to the research interest pursued. The selection of morphological descriptors also depends strongly on the observed taxon. Often, no clear separation can be made between field descriptors and those used for specimens in a collection, such data should be linked directly to the unit. However, a number of characters can only be recorded in the field, such as size measurements of larger plants, some colour characters which may be lost in conserved material, occurrence quantifications, phenological characters, and local ethnobotanical information.
In botany, the development of computerized authority files of plant descriptors, which define the terminology to be used for characters and their states is a very important task. That this is not a simple problem is illustrated by the up to now unsuccessful attempts by the TDWG Descriptors Subgroup (Higher Plants) to develop a minimal set of morphological descriptors (Pankhurst, pers. comm.). It is not the chore of this model to propose such a set of characters. The model allows for subtypes of the Field Descriptors entity to be defined according to the user's needs.
While standardization in morphological characters is a notoriously difficult task, for plant uses such a standard exists (Cook 1995) and should be followed wherever possible. Recording uses at the collection site becomes increasingly important especially in tropical countries. However, the question of intellectual property rights must not be ignored.
Diagram 13: Field descriptors (Entities)
Useful local ethnobotanical information for which a structure can be defined also includes the vernacular name of the plant. For both, uses and vernacular names, a source should be cited.