Fig. 2. Franhueberia gerriennei gen. et sp. nov. (USNM 558725). (A) Transverse section of axis; primary xylem at center, surrounded by secondary
xylem. Slide B21 E b no. 106. Scale = 300 μ m. (B) Radial longitudinal section; primary xylem at center (arrows); asterisk indicates same position as in C.
Slide B21 E(2) s no. 42A. Scale = 100 μ m. (C) Detail of B (asterisk indicates same position as in B). Primary xylem longitudinal section; protoxylem tracheid
with annular-helical thickening (at left, next to asterisk) and metaxylem tracheids with circular and oval bordered pits. Note tracheids with continuous
secondary wall lining interrupted by sparse pitting (right of protoxylem tracheid); oval pits with two apertures per membrane close to the upward tapering
end of a metaxylem tracheid (arrowhead); and metaxylem tracheid with scalariform multiaperturate pits (right). Scale = 40 μ m. (D) Transverse section;
primary xylem at center, with no particular patterning of tracheids (and with taphonomically induced compression and fracturing) surrounded by secondary
xylem exhibiting radial patterning of tracheids. Note inner ends of xylem rays (some indicated by arrowheads). Slide B21 E b no. 85. Scale = 100 μ m. (E)
Transverse section; transition from primary xylem (right; note varied tracheid diameters) to secondary xylem (left); approximate position of transition
marked by arrowheads. Slide B21 E b no. 138. Scale = 40 μ m. (F) Longitudinal section; metaxylem tracheids with circular to oblique-oval bordered pits
(some with double apertures—upper and lower right). Note tracheid with continuous secondary wall lining interrupted by sparse pitting (center). Slide B21
E(2) s no. 42A. Scale = 30 μ m. (G) Longitudinal section; metaxylem tracheids with circular, oblique, and scalariform bordered pits. Slide B21 E(2) s no.
40A. Scale = 30 μ m. (H) Transverse section; multiplicative divisions (arrowheads). Slide B21 E b no. 107. Scale = 30 μ m.