. 2021 Nov 29;10(12):2617. doi: 10.3390/plants10122617

Table 4.

Anatomical characteristics of the stem bark of the five Ulmus species.

Parameters	U. davidiana var. japonica	U. parvifolia	U. macrocarpa	U. laciniata	U. pumila
Number of layers in medullary rays	2.2 ± 0.2 ^b	3.2 ± 0.4 ^a	4.1 ± 1.2 ^a	3.2 ± 0.4 ^a	3.5 ± 0.1 ^a
Frequency of medullary rays (in 1 mm²)	4.3 ± 0.7 ^a	3.3 ± 0.5 ^b	2.9 ± 0.4 ^b	2.9 ± 0.5 ^b	2.8 ± 0.3 ^b
Length of medullary ray cells (µm)	35.9 ± 1.6 ^b	47.0 ± 7.2 ^a	20.2 ± 7.0 ^c	51.4 ± 6.6 ^a	37.4 ± 3.0 ^b
Width of medullary ray cells (µm)	12.6 ± 0.9 ^b	13.3 ± 1.7 ^b	17.0 ± 1.8 ^a	15.3 ± 0.5 ^ab	11.7 ± 2.0 ^b
Ratio of secretary canals (%, in 1 mm²)	20.7 ± 2.8 ^ab	23.4 ± 4.0 ^a	2.5 ± 0.5 ^c	17.6 ± 3.0 ^b	20.0 ± 0.9 ^ab
Frequency of secretary canals (in 1 mm²)	18.4 ± 2.5 ^a	20.5 ± 2.7 ^a	2.7 ± 0.6 ^c	3.2 ± 0.4 ^c	15.5 ± 0.6 ^b
Length of secretary canals (µm)	145.9 ± 9.6 ^b	167.9 ± 11.2 ^a	89.6 ± 11.0 ^e	108.6 ± 11.8 ^d	133.6 ± 1.9 ^c
Width of secretary canals (µm)	169.4 ± 41.3 ^b	237.4 ± 28.8 ^a	129.8 ± 5.5 ^c	191.9 ± 6.5 ^ab	224.5 ± 27.3 ^a

Data are expressed as mean ± SD (n > 3) of five independent experiments. Different upper letters in the same line indicate a significant difference (p < 0.05) among samples.