Rays composed uniquely of ray parenchyma.
No transversal tracheids present.
r
h
Rays with transversal tracheids:
In the interior of the rays are parenchyma cells with simple pits.
The marginal cells are tracheids with bordered pits which are smaller
than the bordered pits of the axial tracheids of earlywood.
r
h
Transversal ray tracheids with tooth-shaped walls.
r
h
Vertical tracheids with biseriate bordered pits.
The thickenings of the walls are called crassulea or bars of Sanio.
r
me
In tangential section the border cells of the rays
present nodular chains due to an intense pitting.
r
me
Ray cells with thin, tangential walls.
r
h
Ray cells with nodular tangential walls.
r
h
Tracheids with distinct spiral thickenings.
r/t
h
Tracheid with helical fissures in the wall structure.
This phenomenon is not useful as an identification characteristic
as it is frequent in compression wood and altered wood of many coniferous
species.
