Table II.

List of symbols and definitions of terms used in the present study

Term	Symbol	Measurement Unit	Definition
Photosynthetically active leaf area	Ap	Percentage of the total leaf area	Leaf area that corresponds to photosynthetically active leaf tissue (obtained from image analysis)
Transparent leaf area	At	Percentage of the total leaf area	Leaf area that corresponds to nonphotosynthetically active leaf tissue (obtained from image analysis)
Transparent leaf area complexity factor	CFAt	mm mm−2	CFAt = TLBSE × At
Photosynthetic capacity per projected leaf area	Pmax	μmol O2 m−2 s−1	Obtained from leaf disk electrode measurements
Photosynthetic capacity per Ap	P*max	μmol O2 m−2 AP s−1	P*max = (Pmax × 100/Ap)
Photosynthetic capacity per unit leaf volume	Pmax,v	μmol O2 m−3 s−1	Pmax,v = (Pmax/T)
Photosynthetic capacity per unit of photosynthetically active leaf volume	P*max,v	μmol O2 m−3 VP s−1	P*max,v = (Pmax,v × 100/Vp)
Leaf thickness	T	mm	Obtained from image analysis
Bundle sheath extensions trace length	TLBSE	mm mm−2	Obtained from image analysis
Photosynthetically active leaf volume	Vp	Percentage of the total leaf volume	Vp = Apa
Transparent leaf volume	Vt	Percentage of the total leaf volume	Vt = Ata
Leaf transparent volume to total leaf surface ratio	λt	mm3 mm−2	λt = (Vt/As) = (At × T/As)b

^a Assuming that the BSEs are perpendicular to the leaf surface (see “Materials and Methods”). 

^b A_s defined as the total leaf surface; see Roderick et al. (1999).