Wataria kvacekii, 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 : 316-320

Wataria kvacekii sp. nov.

Text-fig. 9a–h

H o l o t y p e. Here designated. UF 279-24546 (Textfig. 9a–h).

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.

PFN002682 (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. Species name to honor Zlatko Kvaček, a kind man, who was and will continue to be an inspiration for those who study Tertiary floras.

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

Crook County, Oregon, USA.

Ty 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. Wood ring-porous. Earlywood zone with more than 1 row of earlywood vessels. Vessels solitary and in short radial multiples. Perforation plates exclusively simple.

Intervessel pits alternate, small; vessel-ray parenchyma pits similar to intervessel pits. Vessel elements and imperforate elements regularly or irregularly storied. Axial parenchyma scanty paratracheal to vasicentric and diffuse-in-aggregates. Rays typically less than 10-seriate; heterocellular; commonly> 1 mm high. Tile cells present, Pterospermum- type.

D e s c r i p t i o n. Growth rings present, marked by radially flattened fibers, and differences in diameters of latewood and earlywood vessels of subsequent rings (Textfig. 9a). Wood distinctly ring-porous, earlywood pore zone usually 3 vessels deep.

Vessels predominantly solitary and in occasional radial multiples of 2 in both earlywood and latewood ( Text-fig. 9a ); average tangential diameter of earlywood vessels 143 (33) µm; perforations simple ( Text-fig. 9b ); intervessel pits alternate ( Text-fig.9c ), 3–5 µm in horizontal diameter; vessel-parenchyma pits similar to intervessel pits ( Text-fig. 9d ); vessel element length averages 346 (26), range 310–410 µm; widely spaced thin-walled tyloses present; helical thickenings not observed.

Fibers thin to medium-thick-walled, storied, without distinctly bordered pits; non-septate, tending to be storied structure ( Text-fig. 9e, h ).

Axial parenchyma scanty paratracheal to vasicentric, (diffuse-) diffuse-in-aggregates, strands of 4–8 (Text-

1. Watari (1952), 2. Terada and Suzuki (1998), 3. Jeong et al. (2003), 4. Li et al. (2015), 5. Manchester (1979)

* mean ray heights fig. 9a, b), also chambered with solitary prismatic crystals ( Text-fig. 9e, f ). Rays 1–6-seriate ( Text-fig. 9e ).

Multiseriate rays heterocellular with uniseriate rows of 1–3 cells; Pterospermum- type tile cells present; ( Text-fig. 9f, g ) some rays the same height as the vessel elements and axial parenchyma strands, most rays extending over multiple tiers of the storied parenchyma. Total multiseriate ray height averages 1,075 (634) µm, 320–2,600 µm. 5–8 mm.

Axial parenchyma and vessel elements storied (Textfig. 9e).

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.Tilecells are unique to the Malvales . A search of the InsideWood database for the combination of tile cells (111p) and ringporosity (3p) only returned species of the present-day genera Grewia L. ( Malvaceae /Grewioideae) and Reevesia LINDL. ( Malvaceae /Helicteroideae), and the fossil wood genus Wataria from the Oligocene – Miocene of Asia, whose species were originally assigned to Reevesia ( Terada and Suzuki 1998) .

Ring-porous species of Grewia and Reevesia differ from Wataria kvacekii because their latewood vessels are in clusters.

Comparisons with fossil woods. Rodríguez-Reyes et al. (2014) reviewed the characteristics of fossil malvaceous woods and noted only two genera with distinctly ring-porous species: Reevesia and Wataria . Selmeier (2000b) described semi-ring-porous Grewioxylon with a transition from earlywood to latewood that is gradual. This Post Hammer wood generally conforms to the genus Wataria K.TERADA et MITS.SUZUKI ( Terada and Suzuki 1998), diagnosed as having distinctly ring-porous woods, earlywood vessels mostly solitary with latewood vessels mostly solitary, not in clusters; perforation plates simple; alternate intervessel pitting; helical thickenings absent; storied axial parenchyma, heterocellular multiseriate rays with tile cells. To date, four species of Wataria have been described W. miocenica K.TERADA et MITS.SUZUKI , W. oligocenica K.TERADA et MITS. SUZUKI , W. parvipora K.TERADA et MITS.SUZUKI , and W. yunnanica YAN- JIE LI et OSKOLSKI ( Tab. 4). Species have been distinguished based on number of rows of wide earlywood vessels, latewood vessel grouping, and crystal occurrence (e.g., Li et al. 2015). There also are differences in quantitative features (earlywood vessel diameter, vessel element length, axial parenchyma strand length, ray width and height). Table 4 indicates that this Wataria kvacekii ’s combination of the aforementioned features differs from previously described Wataria species and so consider it a new species. Axial parenchyma is not as easy to see in the Post Wataria wood as it is in the Asian species, but as best we can determine its distribution is similar to other species.

Two types of malvaceous woods were reported from the nearby middle Eocene Nut Beds flora, Clarno Formation, Oregon, both are semi-ring-porous to diffuse-porous, without a well-defined earlywood pore zone ( Manchester and Miller 1978, Manchester 1979, 1980, Wheeler and Manchester 2002). Chattawaya paliforme MANCHESTER also differs because it lacks storied structure and its rays are wider (to 14-seriate). Although not distinctly ringporous, Triplochitioxylon oregonensis MANCHESTER shares many features with this Post Hammer wood: storied structure, intervessel pit size, vessel-ray parenchyma pit type, ray heights, crystals in chambered axial parenchyma. Terada and Suzuki (1998) commented on the similarities between Triplochitioxylon MANCHESTER and Wataria . Triplochitioxylon has longer vessel elements; averages of 440–487 µm vs. average of 346 µm with a maximum of 410 µm for Wataria kvacekii . This difference likely is related to most measurements for the Post Wataria being of the barrel-shaped earlywood vessel elements. Wide earlywood vessel elements are shorter than the narrow latewood vessels (e.g., Süss 1967, Kitin et al. 1999); it’s been suggested that the widening of earlywood vessel elements in ring-porous woods results in their shortening ( Chalk and Chattaway 1935). It is tempting to hypothesize that Wataria kvacekii belongs to the same lineage as Triplochitioxylon and that the differences in porosity between them are associated with the increasing seasonality in the transition from the middle Eocene to the late Eocene.

C o - o c c u r r i n g f r u i t s / s e e d s. Malvaceae recognized from fruits from the Teater Road locality include Craigia W.W.SM. et W.E.EVANS and the extinct genus Florissantia KNOWLT. ( Manchester 1992: figs 34,

35, 37–40). Extant Craigia wood is distinguished from the fossil wood treated here by its helically thickened vessel elements, wider rays (>10-seriate), and lack of storied structure ( Manchester et al. 2006). Fossils of flowers and fruits with the distinctive persistent calyx of Florissantia occur in eastern Asia ( Manchester 1999: fig. 7B) as well as at various localities in North America. Pollen from the anthers of Florissantia flowers is similar to that of Tilia L. and Craigia ( Manchester 1992, Kvaček et al. 2005). Based on circumstantial evidence of co-occurrence, it is possible that Wataria / Triplochitioxylon trees may have borne flowers corresponding to the genus Florissantia .

Figures

Text-fig. 9. Wataria kvacekii sp. nov., UF 279-24556. a: Wood ring-porous, earlywood with 2–3 rows of wide pores, vessels solitary and in radial multiples of 2, axial parenchyma scanty vasicentric and some apotracheal diffuse-in-aggregates, TS. b: Series of vessel elements with simple perforations, axial parenchyma strands adjacent to vessels, RLS. c: Alternate intervessel pitting, vessel element end walls horizontal, RLS. d: Vessel-axial parenchyma pitting similar to intervessel pitting, RLS. e, f: Rays with tile cells, storied axial parenchyma, some strands chambered crystalliferous, TLS. g: Detail of ray, TLS. h: Storied imperforate elements. Scale bars: 200 µm in a; 100 µm in b, e; 50 µm in c, d, f, h; 20 µm in g.