affinis (or sp. aff = species affinis) is used
when the identity of a distinct biological
species is unknown but it
has a striking similarity or close relation with a known
Trichocaulon aff. flavum, means a distinct
species of Trichocaulon which is similar or has affinity
with T. flavum but is NOT T. flavum, but a related
species not exactly identical to it. An
taxonomic study will decide to confirm if it is the same or
Alternative use of the term "sp. aff. or affin."
and “cf.” in
- "sp. aff. or affin."
(Latin for affinis = related to) as used in scientific papers,
indicates that the
specimen is closely related to the named
species but show features
that make it obvious that it is a different species.
- "cf." (Latin for
confer = compares with) is used in similar papers to indicate
that the specimen
resembles the named species
very closely, but has certain minor features not found on the
specimens. Whether it is a different
of the named species or a different species altogether would
require more research into the species' population
than was undertaken by the
In practical terms the
author decides whether to use "cf." or "sp. aff."
based on his own experience