ULMUS L. (1753)

CF. ULMUS WOODII WHEELER AND MANCHESTER, 2007

FIG. 11A–F

Description— Growth ring boundaries distinct (1p). Wood semi-ring-porous to ring-porous (3p, 4p). Latewood vessels in radial multiples and clusters (11p) arranged in wavy tangential bands (6p) (Fig.11A–C). Mean tangential diameters of earlywood vessels 70 (SD=13) µm, range 48–87 µm. Perforation plates exclusively simple (13p, 14a). Intervessel pits crowded alternate (22p), polygonal in outline (23p), not vestured (29a), 7–11 µm in horizontal diameter (26p 27p); vessel-ray parenchyma pits similar in size to intervessel pits with borders somewhat reduced (31p) (Fig. 11D). Vessel element lengths 139–214 µm (n=7). Widely spaced thin-walled tyloses present.

Fibers non-septate (66p), pits not observed (62a).

Axial parenchyma paratracheal, non-crystalliferous strands usually 4 cells.

Rays mostly 3–5-seriate (98p), uniseriate rays not common (Fig. 11E,F); homocellular composed of procumbent cells (104p) (Fig. 11D); multiseriate ray heights average 267 µm (SD=95), range 146–444 µm.

Solitary prismatic crystals in chambered axial parenchyma strands, not in ray parenchyma (136p 138a 142p) (Fig. 11D,F).

Pith composed of thin-walled isodiametric parenchyma.

Specimens— UF 278-62702, 84866, 84880, 84883, estimated maximum diameters of 4 cm, 2 cm with pith, 1.1 cm with pith.

Comments— Because of the tyloses, we could only measure seven vessel element lengths.

Comparisons with extant and fossil woods— These Dietz Hill (UF 278) specimens are small axes so we did not use quantitative features in our searches of InsideWood. We used the IAWA features given in the description above to search InsideWood, varying porosity type.

The search of the modern wood database using ring-porosity (3p) yielded Maclura pomifera (rays consistently narrower, latewood clusters not as discrete as in this wood, tyloses closely spaced and bubble-like) and eight species of Ulmus . Results of a search of the IW fossil wood database, excluding incomplete descriptions, returned one species of Ulmoxylon and two species of Ulmus . When semi-porosity is used, only two fossil wood species are returned U. danielii Wheeler and Manchester (2007) and U. woodii Wheeler and Manchester (2007), both from the nearby Post Hammer (UF 279) locality. Ulmus danielii varies from diffuse-porous to semi-ring-porous, while U. woodii varies from semi-ring-porous to ring-porous. Thus, we consider UF 278-84866, 84883, and 62702 to belong to U. woodii .