A coding question

Joseph H. Kirkbride, Jr. jkirkbri at ASRR.ARSUSDA.GOV
Tue Mar 25 17:50:48 CET 1997


As many of you are aware, we are now working on a DELTA database for the 
fruits and seeds of the genera of Faboideae (Fabaceae). The database has 
316 characters and 454 genera.

The fruit wall is made up of three layers: epicarp, mesocarp, and 
endocarp. The presence or absence of these layers and their fusion or 
separation are useful characteristics. So, we have the following three 
characters:

#115. mesocarp <occurrence>/
       1. present/
       2. absent/
#143. endocarp <fused to or separating from epicarp and mesocarp>/
       1. remaining fused to mesocarp and epicarp <IMPLICIT>/
       2. separating from mesocarp/
       3. separating with mesocarp from epicarp/
#144. endocarp <fused to or separating from epicarp when mesocarp
          absent>/
       1. remaining fused to epicarp/
       2. separating from epicarp/

When the mesocarp is present (115,1), 143 is used for the fusion or 
separation of the epicarp, mesocarp, and endocarp. When the mesocarp is 
absent (115,2), 144 is used for the fusion or separation of the epicarp 
and endocarp.

When I established the dependencies 115,1:144 and 115,2:143, three 
genera are reported as "Controlling character not coded. ... 115:143". 
All three genera are in the same situation; character 115 is coded as 
115,U. These are very rare genera with very few fruits. To determine the 
presence or absence of the mesocarp, a fruit valve must be cut or broken 
to examine the layers. For these three genera, we do not have valves 
that we can cut or break. It is obvious that the layers are not 
separating, but we do not know if the mesocarp is present or absent.

For the database to give the best results, the dependencies 115,1:144 
and 115,2:143 should be in operation, but because of the three unknown 
genera, it will not function with the dependencies in place. Does anyone 
reading DELTA-L have a clever work around for this situation?

Joseph H. Kirkbride, Jr.
USDA, Agricultural Research Service
Systematic Botany and Mycology Laboratory
Room 304, Building 011A, BARC-West
Beltsville, Maryland 20705-2350 USA
Voice telephone: 301-504-9447
FAX: 301-504-5810
Internet: jkirkbri at asrr.arsusda.gov



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