SPECIES DESCRIPTIONS FROM REFERENCE CULTURES
Many published descriptions
of species are difficult to use in defining new species (being unique from existing
ones) or in identifying named species. The problems that led to this state of
affairs are numerous. One is just the nature of science: its hard to be accurate
and complete when not much is known about the organisms in question--and that
was the stage we were at only 30 years ago! The other is that the morphological
characters being used to describe species are component parts of basically a
single multinucleate cell, and they are often hard to see and manipulate. They
also are subject to change from natural senescence or from many biotic or abiotic
factors. The natural propensity for mycologists to collect and identify field-collected
material just doesn't work that well for arbuscular fungi, unless of course
that person already has an excellent idea of what healthy specimens look like.
With the disparity between
information in descriptions and that obtained from healthy specimens in collection
pot cultures, INVAM has been forced to assign a reference
culture for each unique morphotype. If the morphotype could be linked confidently
to a type specimen or to a description, then it is assigned the Latin name and
a complete diagnosis was generated. It is these diagnoses which have been converted
to "species information pages" on this website. The format is standardized
for ease of comparison and locating similar types of structures. Species which
our grouping criteria indicate need to be synonymized (e.g., G. claroideum
and G. fistulosum) remain separate here until formal action is
taken in the literature. However, the hypotheses of synonymy are presented here
so that everyone can begin to see where morphology overlaps in a continuum of
variation and where it is discrete and unique.
The terminology used to
define and describe structures of taxonomic significance does not follow published
conventional definitions. Instead, it is
based on developmental concepts which reflect
more naturally the nature of a structure, how it arises, how it changes during
maturation (differentiation), and how it relates (positionally and developmentally)
to neighboring structures. Please note that not all species have a page on-line,
and some of those that are on-line do not yet have all the support photographs
in place. This is a time-consuming process and photos will be added as time
permits. Starred species are in the process of being described from INVAM cultures.
These pages are meant to
allow the viewer to gain familiarity with important morphological taxonomic
diagnostic characters for each species. Viewers who have published descriptions
in their files will notice that often there is various degrees of disparity
between protologue details and those in these web pages. It is a useful exercise
to examine (i) if the specimens used to classify the fungus were collected from
field soils or pot cultures, (ii) date of the publication (relative to definition
of new characters), and (iii) taxonomic experience and expertise of the authors
and thus obtain some insight into the taxonomic problems associated with Glomerales.
We encourage the viewer to download text and photographs to organize the information
in applications on your computer in ways that can help in species diagnosis.
Please keep in mind that the photographs are copyrighted and should not be used
in publications or for commercial gain without our express permission.
GLOMUS
PARAGLOMUS
ACAULOSPORA
ARCHAEOSPORA
ENTROPHOSPORA
GIGASPORA
SCUTELLOSPORA
TYPES AND TIDBITS (information from sources other than INVAM reference cultures)
