Phyllode cross-section
Determine transverse sectional shape (t.s.s.) of phyllode.
For non-flat phyllodes the most reliable way of determining t.s.s. is to section phyllode and observe cut end at x10 magnification or higher. Alternatively, roll phyllode between index finger and thumb while carefully observing surface under magnification.
On dry specimens it can be especially difficult deciding which State of this Feature is applicable: as a rule it is best to select multiple States if in doubt, or alternatively, omit this Feature altogether.
Plano-convex. Flat on upper surface and convex on lower surface. This State is rare in Acacia.
This Feature has greatest discriminating power when phyllodes are not flat.
Also, if you have already used Phyllode width in the current identification session then this Phyllode cross-section Feature will have limited discriminating power and can therefore be omitted if you wish.