Keteleeria farjonii, Wheeler & Manchester & Baas, 2023

Wheeler, Elisabeth A., Manchester, Steven R. & Baas, Pieter, 2023, A late Eocene wood assemblage from the Crooked River Basin, Oregon, USA, PaleoBios 40 (14), pp. 1-55 : 2-4

KETELEERIA FARJONII SP. NOV.

FIG. 2A–G

Diagnosis— Growth rings distinct. Gradual transition from earlywood to latewood. Intertracheary bordered pits primarily uniseriate, occasionally biseriate, on radial walls. Axial parenchyma absent to rare. Rays exclusively uniseriate, average ray height medium (sensu IAWA Committee 2004, 5‒15 cells), ray tracheids absent to rare, cross-field pits cupressoid to taxodioid, 2‒4 pits per cross-field, horizontal end walls of ray parenchyma pitted. Axial canals with thick-walled epithelial cells present; radial canals absent.

Holotype — UF 278-84891 , estimated maximum diameter 4 cm.

Occurrence— Dietz Hill ( UF 278).

Etymology— Named for Aljos Farjon, THE expert on all things coniferous.

Description— Growth rings distinct. Gradual transition from earlywood to latewood ( Fig. 2A‒C ). Average tangential diameter of longitudinal tracheids 24 (SD=4.7), range 13–33 µm; intertracheary bordered pits primarily uniseriate, occasionally biseriate, on radial walls ( Fig. 2E, F ).

Axial parenchyma not observed with certainty ( Fig. 2A‒C ).

Rays uniseriate ( Fig. 2D ); 2‒18 cells, average 8 (SD=4) cells; 176 (SD=87) µm high, 67‒358 µm; only ray parenchyma observed ( Fig. 2E–G ); end walls of ray parenchyma nodular ( Fig. 2G ); horizontal walls of ray parenchyma apparently pitted ( Fig. 2G ); cupressoid/taxodioid pits, 2‒4 pits per cross field, mostly two. ( Fig. 2E‒G ).

Ray tracheids apparently absent. Normal and traumatic axial canals present with rather thick-walled epithelial cells ( Fig. 2A‒C ). Radial canals absent.

Comparisons with extant and fossil woods— The only extant conifer with axial resin canals (normal and traumatic), but without radial resin canals is Keteleeria . Other features we observed in UF 278-84891 are consistent with its assignment to this genus: cupressoidtaxodioid cross-field pits, nodular end walls of ray parenchyma (e.g., Phillips 1948, Lin et al. 2000, Lin et al. 2002, Itoh et al. 2022).

Today, Keteleeria (three to five species) is native to the broadleaved evergreen forests of Central and South China, Laos, Vietnam, and Taiwan ( Farjon 1990, Shu 1999, POWO 2023). It is another example of an Asian endemic that had a more extensive range in the past. Its distinctive seeds are known from the Eocene and Oligocene of North America ( Meyer and Manchester 1997, Manchester et al. 2009), as well as the Oligocene-Miocene of Europe ( Manchester et al. 2009).

Shi et al. (2022) reviewed the record of fossil woods resembling Keteleeria and described a new species Keteleerioxylon changchunense Shi, Sun, Meng et Yu (2022) from the early Cretaceous of China. There are three other reports of Keteleerioxylon I.A. Shilkina (1960) from the Cretaceous, Oligocene, Pliocene, Miocene of Russia ( Shilkina 1960, Blokhina and Bondarenko 2005, Blokhina et al. 2006). However, those woods and the Miocene Keteleeria wood described from the Miocene of Japan ( Choi et al. 2010) differ from UF 278-84891 in having cells that resemble ray tracheids. Such cells appear absent from this Dietz Hill wood. Given that it has a combination of features only seen in extant Keteleeria , we are assigning it to the genus.

Figures

Figure 2. Pinaceae. Keteleeria farjonii, UF 278-84891. A‒C. Distinct growth rings, gradual transition from earlywood to latewood, traumatic resin canals, TS. D. Uniseriate rays, TLS. E, F. Intertracheary pitting mostly uniseriate, rays composed of ray parenchyma cells, RLS. G. Mostly two pits per cross-field, difficult to determine if taxodioid or cupressoid; n to left of nodular end wall; p above pitted horizontal walls, RLS. Scale bars=500 µm in A; 200 µm in B; 100 µm in C, D; E; 50 µm in F; 20 µm in G.