cf./aff.

[Bentivenga, Stephen P]

This topic seems such hotbox for discussion that I felt compelled to stick my t
wo cents in.

In our collection we have adopted the use of simple modifiers to reflect less t
han certain identifications.  When a specimen is similar to our concept of a na
med species, but differs in at least one character we add "-like" to the end of
 the name.  When a specimen is similar to a named species but we are unsure if
it is really that species we add a "?" at the end of the epithet.  Thus, Glomus
 clarum-like is most similar to Glomus clarum but differs in at least one chara
cter of unknown phylogenetic significance.  Conversely, Glomus clarum? is simil
ar to Glomus clarum but we are unsure of its exact placement, either because we
 haven't spent the time thoroughly evaluating the specimen, or because our spe
cies concept of Glomus clarum is in a state of flux.  These approaches appear t
o be anologous to how  many taxonomists use aff. and cf., respectively.  Howeve
r, when we have used these modifiers in print (as in our catalog), we made a sp
ecific point of DEFINING our usage to avoid ambiguity.

This brings up two important points.  First, taxonomists have a responsibility
to functionally define terms at each usage, so that readers (both contempory an
d future) can clearly relate the work at hand to the remaining literature.  How
 elso can we expect to maintain continuity in a body of literature.  When ambig
uities are not resolved, the worth of a manuscript decreases sharply.  We may n
ot be able to resolve the ambiguity for the science as a whole (that would requ
ire broad agreement among taxonomists), but we can and MUST resolve these probl
ems in individual works.

Second, these problems (eg., use of aff./cf.) seem particularly acute in taxa f
or which our species concepts are poorly defined.  That is the case in our coll
ection of fungi (order Glomales).  Many species in this order differ in only on
e or two microscopic characters, and our concepts of species boundaries are con
stantly shifting.  Furthermore, we have almost as many undescribed species as d
escribed ones.  I suspect this is also the case for many taxa that are understu
died (maybe most taxa!).  In all likelihood, our species concepts in 50 years w
ill be quite different from current concepts.  Therefore, our definitions used
today must be sufficiently clarified so that they can be correctly interpreted
in the future.

With that, I will get off my soap box and get on with the work at hand. Someone
 just set some samples on my desk that are crying out to be named ......(fungi
have very high-pitched, squeaky voices that can only be heard by sleep-deprived
, slightly neurotic researchers)


- Steve

Stephen P. Bentivenga
Division of Plant and Soil Sciences
West Virginia University