Table 1.

Frequency of initially wider or branched hPEDs in the first, second and third intercostal areas (IAs) of the first leaf.

	#Wider hPEDsa	#Branched hPEDb	Total # hPEDs observed	Frequency wider hPEDs	Frequency branched hPED
1st IA	17	3	86	19.8%**	3.5%*
2nd IA	56	22	91	61.5%**	24.2%*
3rd IA	23	4	32	71.9%**	12.5%*
Total	96	29	209	45.9%**	13.5%*

^aInitially wider hPEDs were defined as hPEDs that were more than two cells wide at first appearance.

^bBranched hPEDs were defined as freely-ending hPEDs that formed side branches.

^**The distribution of wider hPEDs across the 1, 2, 3rd IA differs significantly from null hypothesis of even distribution to P = 0.001.

^*The distribution of branched hPEDs across the 1, 2, 3rd IA differs significantly from null hypothesis of even distribution to P = 0.01. Significance was calculated using the Chi-squared test for a 2 × 3 contingency table, assuming two degrees of freedom.