Measure spore length along the long axis of the spore.

For measurement features we recommend entering the midpoint of the observed range. Thus, if the range is 5-10 micrometres, enter the value 7.5. Alternatively you may enter the full range (such as 5-10), but this will tend to retain more taxa since taxa that overlap even slightly with the range entered will be retained.

Entering only the value for the smallest or largest spore is not recommended because exceptional spores may be outside of the coded range for a taxon, whereas the midpoint of the observed range is unlikely to fall outside the coded range.