Table 2 Anatomical characteristics of Piper stems in Taiwan (transverse sections)
Characteristic | Piper arborescens | P. betle | P. kadsura | P. kawakamii | P. kwashoense | P. sintenense | P. taiwanense |
|---|---|---|---|---|---|---|---|
Shape | Oblate | Oblate | Transversely elliptica | Oblate | Oblate | Transversely elliptica | Oblate |
Phloem bundles | Arcuate | Rounded-elongate | Triangular | Arcuate | Arcuate | Arcuate | Rectangular to triangular |
Mvb number | 9–13 | 12–19 | 5–11 | 6–7 | 12–14 | 4–7 | 6–9 |
Pvb number | 30–31 | 30–40 | 15–23 | 21–22 | 34–41 | 16–23 | 21–26 |
Ray width (μm) | 37–251 | 129–617 | 55–493 | 38–603 | 80–294 | 106–276 | 66–342 |
Vessel diameter (μm) | 4–128 | 18–217 | 9–125 | 10–167 | 10–145 | 7–100 | 6–197 |
Vessel arrangement | 2 | 2 | 2 | 1 | 1 | 2 | 1 |
Sclerenchyma ring | 1 | 0 | 1 | 1 | 1 | 1 | 1 |
Furrowed xylem | 0 | 1 | 0 | 0 | 0 | 0 | 0 |
Parenchyma proliferation | 0 | 1 | 1 | 0 | 0 | 1 | 1 |
Mc | 1 | 1 | 1 | 1 | 1 | 0 | 0 |
Mc dispersed in cortex | 0 | 1 | 0 | 0 | 0 | 0 | 0 |
Central mc in pith | 1 | 1 | 1 | 1 | 1 | 0 | 0 |
Pericycle | 1 | 0 | 0 | 0 | 1 | 0 | 1 |