Base cordate

A base is cordate if the basal parts of the lamina extend basally (below) beyond the juncture of the petiole and the lamina (Figures AQ - AT).

AQ) Cordate base	AR) Cordate base	AS) Cordate base	AT) Cordate base

Base round

A base is round if the most basal fourth of the lamina has a convex margin (Figures AU - AY).

AU) Round base.	AV) Round base.	AW) Round base.	AY) Round base.

Base acute

A base is acute if the most basal fourth of the lamina has a straight or concave margin (Figures AZ to BC).

AZ) Acute base.	BA) Acute base.	BB) Acute base.	BC) Acute base.

Note that this definition of acute does not depend on the angle formed by the lamina sides.