Fagus dodgei, Wheeler & Manchester, 2021

Wheeler, Elisabeth A. & Manchester, Steven R., 2021, A Diverse Assemblage Of Late Eocene Woods From Oregon, Western Usa, Fossil Imprint 77 (2), pp. 299-329 : 306-308

Fagus dodgei sp. nov.

Text-fig. 4a–h

H o l o t y p e. Designated here. UF 279-34468 (Textfig. 4a, b, d–h). Minimum estimated axis diameter 10 cm.

A d d i t i o n a l m a t e r i a l. UF 279-30165 (Textfig. 4c).

P l a n t F o s s i l N a m e s R e g i s t r y N u m b e r.

PFN 002679 (for new species).

R e p o s i t o r y. Paleobotany Collections , Florida Museum of Natural History , Gainesville, Florida, USA .

E t y m o l o g y. Named for William W. Dodge IV, who made sure paleoxylotomy in North Carolina was alive and well during the Covid-19 pandemic.

T y p e l o c a l i t y. UF 279. About 3 km east of Post,

Crook County, Oregon, USA.

T y p e s t r a t u m a n d a g e. John Day Formation,

Eocene.

D i a g n o s i s. Growth rings distinct. Diffuse-porous to semi-ring-porous. Vessels mostly solitary, but also in occasional radial, oblique, or tangential pairs; tangential diameters average <100 µm; perforations simple and scalariform; intervessel pits opposite, transitional to scalariform; pits to ray parenchyma oval to horizontally elongate, with reduced borders. Non-septate fibers with distinctly bordered pits on radial walls. Axial parenchyma diffuse and diffuse-in-aggregates as short uniseriate bands. Rays uniseriate and multiseriate, tending to be of two sizes, wider multiseriate rays>10-seriate; wide rays irregularly spaced; average multiseriate ray height> 1 mm; homocellular to heterocellular, body composed of procumbent cells with marginal rows of square and upright cells. Solitary rhomboidal crystals occasional in procumbent ray cells. Storied structure absent.

D e s c r i p t i o n. Growth rings distinct, marked by radially narrow fibers, and differences between latewood and earlywood vessels of subsequent rings (latewood vessels are narrower and not as crowded as earlywood vessels) (Textfig. 4a, b). Diffuse-porous to semi-ring-porous ( Text-fig. 4a ).

Vessels mostly solitary, but also occasional radial, oblique and tangential pairs; average earlywood tangential diameter 55 (11), range 39–79 µm; vessel frequency in first half of growth ring ca. 90/mm 2; perforations simple and scalariform with 4-24 bars, mostly 8–12 bars (Textfig. 4d, e); intervessel pits opposite (5–7 µm), transitional to scalariform ( Text-fig. 4c ); pits to ray parenchyma oval to horizontally elongate, with reduced borders ( Text-fig. 4f ); vessel element lengths 450–520 µm.

Non-septate fibers with distinctly bordered pits on radial walls.

Axial parenchyma apotracheal, diffuse as isolated cells and diffuse-in-aggregates as short uniseriate bands, more easily seen in latewood ( Text-fig. 4a ).

Rays uniseriate and multiseriate, tending to be of two sizes, with rays 1–5(–6)-seriate common, and wider multiseriate rays to 18–20-seriate, with few intermediate widths; wide rays irregularly spaced ( Text-fig. 4g, h ); average multiseriate ray height 1.56 mm, range 0.74–2.69 mm; homocellular to heterocellular, body composed of procumbent cells usually with 1–4 (up to 8) marginal rows of square and upright cells.

Solitary rhomboidal crystals occasional in procumbent ray cells. Storied structure absent.

C o m p a r i s o n s w i t h e x t a n t w o o d s. The following combination of features indicates affinities with Fagus (Fagaceae) : distinct growth rings (1p), simple and scalariform perforation plates (13p 14p), opposite intervessel pitting (21p), vessel-ray parenchyma pits with reduced borders (30a), narrow numerous vessels (42a 43a 46a 47a), non-septate fibers with distinctly bordered pits on radial walls (62p 66p), diffuse and diffuse-in-aggregates axial parenchyma (76p 77p), wide rays>10 cells wide and> 1 mm high (99p 102p). To the best of our knowledge, there is not a reliable means of distinguishing present-day Fagus species based on wood anatomy alone ( Brazier and Franklin 1961, Wheeler and Dillhoff 2009).

Woods of the Platanaceae are common in the Paleogene of the western USA. and superficially resemble Fagus . However, there are features useful in distinguishing them (e.g., Panshin and DeZeeuw 1980, Hoadley 1990). Fagus consistently has vessel-ray parenchyma pits with reduced borders that are somewhat horizontally elongate, while Platanus L. has vessel-ray parenchyma pits similar to intervessel pits. Vessel multiples are rare in both, but Platanus has some tangential multiples and a tendency to vessels being tangentially arranged; consequently, intervessel pits are more common in Platanus than in Fagus . Intervessel pits are consistently opposite in Platanus ; while Fagus usually has transitional (opposite- scalariform) intervessel pitting. Spacing of and size of the wide rays is more uniform in Platanus than in Fagus . All these features can be reviewed in the InsideWood image collection (InsideWood 2004-onwards).

C o m p a r i s o n s w i t h f o s s i l w o o d s. Fagus - like woods have been described as species of Fagus , Fagoxylon STOPES et fUJII, and Fegonium UNGER ( Süss 1986) . Descriptions of most lack details that would permit confirming their relationships with Fagus . There are at least ten Fagus -like woods reported from the Mio-Pliocene of Europe ( Gregory et al. 2009), but their descriptions are brief, so it is not possible to do detailed comparisons of them with this late Eocene wood.

There are differences between Fagus dodgei and the midMiocene Fagus manosii E.A.WHEELER et T.A.DILLHOff from Washington State, USA ( Wheeler and Dillhoff 2009), which had more scalariform intervessel pits and larger opposite intervessel pits, narrower and shorter rays (to 16-seriate and 1.7 mm high), less axial parenchyma, and lacked crystals. Thus, although there is no reliable way to distinguish between extant species of Fagus , we are choosing to recognize Fagus dodgei as a new species to emphasize that it differs from the mid-Miocene Vantage Fagus wood.

R e m a r k s. Denk and Grimm (2009) proposed that Fagus evolved in the Northern Pacific Region. Fossil species of Fagus , based on fruits and leaves, are known from the Paleogene of the Pacific Northwest. The middle Eocene Fagus langevinii MANCHESTER et R.M.DILLHOff from McAbee, British Columbia, and Republic, Washington, differs from the early Oligocene Fagus pacifica R.W.CHANEY from the Bridge Creek flora of Oregon ( Manchester and Dillhoff 2004).

C o - o c c u r r i n g f r u i t s. A single silicified Fagus nut was recovered from the same locality, UF 279 ( Manchester and McIntosh 2007).

Figures

Text-fig. 4. Fagus dodgei sp. nov., a, b, d–h: UF 279-34468; c: UF 279-30165. a: Wood diffuse-porous to semi-ring-porous with distinct latewoodzone with narrower vessels; vessels solitary andin short multiples;diffuse, diffuse-in-aggregatesaxial parenchyma visible in latewood, TS. b: Growth ring boundary, TS. c: Opposite intervessel pitting, TLS. d: Scalariform perforation plate with fewer than 10 bars, RLS. e: Simple perforation plates (PP), RLS. f: Vessel-ray parenchyma pitting with reduced borders and frequently oval in outline, RLS. g: Rays 1–4(–5)-seriate with variable numbers of marginal rows, TLS. h: Rays of two distinct sizes, widest rays>10-seriate, TLS. Scale bars: 200 µm in a, h; 100 µm in b, e, g; 50 µm in d, f.