FAGUS DOGEI WHEELER & MANCHESTER, 2021

FIG. 8A–K

We found five samples that have a combination of features indicating affinity with Fagus . There is variation in vessel frequency, ray size, and occurrence of compound rays. The abundant tyloses in some samples made it difficult to measure vessel element lengths and to clearly see perforation plates. A description of the features they share is given below. Table 2 gives information on each sample’s vessel diameter and frequency, and ray width and height.

Description— Growth rings distinct, marked by radially flattened latewood fibers, and differences in vessel diameter between latewood and earlywood of subsequent rings (Fig. 8A, B).

Diffuse porous to semi-ring porous (Fig. 8A, B). Vessels predominantly solitary (Fig. 8B); vessels circular to oval to slightly angular in outline; vessels narrow. Perforation plates simple and scalariform with <10 bars (Fig. 8D–F); intervessel pitting scalariform to opposite (Fig. 8G), occasionally alternate; vessel-ray parenchyma pits oval to horizontally elongate with reduced borders (Fig. 8H). Vessel element lengths medium. Tyloses common, usually oriented horizontally across the vessel lumens (Fig. 8K).

Fibers non-septate, walls thick to very thick, with distinctly bordered pits in radial and tangential walls (Fig. 8G).

Axial parenchyma diffuse, less commonly diffuse-in-aggregates (Fig 8A, B), strands of 4–8 or more.

Rays of two distinct sizes, narrow rays 1–3 (-4) seriate and the wider rays more than8-seriate (Fig.8I–K). Homocellular, composed of procumbent cells or heterocellular with body of procumbent cells and 1–4 marginal rows of square/upright cells. Compound rays rare to common.

Specimens— UF 278-84869, 84873, 84888, 84896, estimated maximum diameters 15 cm, 18 cm, 26+ cm, 16+ cm.

Occurrence— Dietz Hill (UF 278).

Comparisons with extant woods— The combination of diffuse-porosity (5p), predominantly solitary vessels (9p), simple and scalariform perforation plates with few bars (13p, 14p, 15p), scalariform and opposite intervessel pitting (20p, 21p), vessel-ray parenchyma pits with reduced borders (31p), average tangential diameter less than 100 µm (42a, 43a), more than 40 vessels per mm 2 (46a–48a), non-septate fibers with bordered pits (62p, 66p), diffuse axial parenchyma unaccompanied by obvious paratracheal parenchyma (76p, 79–86a), rays more than 3-seriate, commonly more than 1.0 mm high, and of two distinct sizes (96a, 97a, 102p, 103p) occurs in Fagus . This combination of features also occurs in the Indian species Vaccinium leschenautii Wight which differs in having helical thickenings in its vessel elements and sheath cells in its rays.

A review of tangential sections of Fagus in the FFPRI Database of Japanese Woods (https://db.ffpri.go.jp) and the InsideWood image collection shows considerable variation in maximum ray width within the illustrated species: Fagus crenata Blume (1849), F.grandifolia Ehrh. (1788), F. japonica Maxim. (1887), F. orientalis Lipsky (1898), and F. sylvatica L. (1753). Compound rays are more common in the Dietz Hill Fagus than in extant Fagus, although compound rays were observed in some samples of F. grandifolia and F. orientalis . Scalariform intervessel pitting is more common in the Dietz Hill Fagus than in modern Fagus .

Figure 8. Caption on pg. 17.

Fagus and Platanus wood are superficially similar. Differences between them were reviewed by Panshin and DeZeeuw (1980), Hoadley (1990), and Wheeler and Manchester (2021). They include: 1) Fagus consistently has vessel-ray parenchyma pits with reduced borders, while Platanus has most vessel-ray parenchyma similar to intervessel pits, and only occasionally with reduced borders; 2) intervessel pits in Fagus are opposite-scalariform (transitional) to occasionally alternate, while in Platanus they are usually crowded opposite; 3) many samples of Fagus tend to be semi-ring-porous with a distinct latewood zone with narrower vessels, while Platanus is most commonly ‘classic’ diffuse-porous; 4) spacing and sizes of the wide rays is more variable in Fagus than in Platanus; 5) the ratio of narrow (1–3-seriate) rays to wide rays (>8-seriate) is higher in Fagus than in Platanus, e.g., we observed ~9: 1 in F. grandifolia and ~2: 1 in Platanus occidentalis L. (1753).

Comparisons with fossil woods— The nearby Post Hammer locality (UF 279) has two samples of beech wood, both assigned to Fagus dodgei Wheeler and Manchester (2021) and which differed from the mid-Miocene F.manosii Wheeler and Dillhoff (2009) from the Vantage Fossil Forests of Washington State which has more scalariform intervessel pitting and shorter rays. Compound rays were not observed in F.manosii . We assign the Dietz Hill (UF 278) woods to F. dodgei; differences between these UF 278 samples and F. dodgei from the Post Hammer locality are comparable to the intraspecific variation seen within present-day F. grandifolia and F. orientalis .

The oldest well-documented occurrence of the beech genus is F. langevinii Manchester and Dillhoff (2004) from the early middle Eocene McAbee flora of British Colombia, based on cupules, nuts, foliage, and associated dispersed pollen, which was considered closest to the Fagus group that includes F.grandifolia (Manchester and Dillhoff 2005). Other Cenozoic North America Fagus megafossil occurrences include F.pacifica Chaney (1925) from the Oligocene Bridge Creek flora of Oregon (cupules and leaves; Chaney 1927, Meyer and Manchester1997), F. idahoensis Chaney and Axelrod (1959), and F.washoensis LaMotte (1936) from the Miocene of Idaho and Oregon (Chaney and Axelrod 1959). The Eurasian fossil record of Fagus based on leaves and cupules, has been reviewed previously (Kvacek and Walther 1991, Tanai 1974, Denk et al 2002). The tricolporate pollen of Fagus, which is distinctive in its ornamentation as viewed in SEM, has been recognized in the Paleocene of Greenland (Grimsson et al 2016), early Eocene of China (Hofmann et al. 2019) and various sites in the Miocene of Europe (e.g., Denk and Bouchal 2021).

Today, F. grandifolia is North America’s only species of Fagus . It has an extensive range in the eastern half of the continent. Renner et al. (2016) reviewed the biogeographic history of the genus. They proposed that there was a Pacific-North American lineage that diverged from a Eurasian lineage by the Middle Eocene. The beech woods from UF 278 and UF 279 are likely part of that Pacific-North American lineage.