Spores - THE definative taxonomic feature??

[R.N. Weinstein]

What do you all think?:

Is there a consensus that spore SIZE, within a range, and spore SHAPE is 
enough to be the last word in species identification?  This seems to be the 
current state of affairs in fungal taxonomy.  Is this system a relic, or 
is it perhaps just a matter of it being the best system around by default?

I have isolated a fungus from Antarctic soils which was initially identified 
to genus Humicola.  This fungus appears to be truly psychrophilic, 
growing so far at temps as low as -2 C but not at temps above 20 C.  
Submitted for a more precise identification, it was identified as Humicola 
fuscoatra.

We then obtained a culture of H.fuscoatra and found that its 
temperature/growth range was the opposite of my isolate: it did not grow 
at +5 C, but grew robustly at 25 C.  Its growth FORM (in a petri dish) 
was very different from mine: H. fuscoatra was white and fluffy (lots 
of aerial mycelium); mine dark and swirly growing into the agar.

However, according to the institute doing the identification, it all 
comes down to spore size and shape.  And so, without using molecular 
techniques and doing a thesis's amount of work to prove a difference in 
species, this appears to be the answer I must settle for.

Does this seem right?  Opinions please!


Rick Weinstein
University of Cambridge