Palaeocarpinus dakotensis

Name

Palaeocarpinus dakotensis

Rank

Species

Generic Name

[Genus] Palaeocarpinus

Authors (Pub.)

Manchester S. R. Pigg K. B. Crane P. R.  

Publication

Palaeocarpinus dakotensis sp.n. (Betulaceae: Coryloideae) and Associated Staminate catkins, pollen, and leaves from the Paleocene of North Dakota [2004/11]

Journal

International Journal of Plant Sciences

Volume

165

Issue

6

Page number

1136

Year

2004

Fossil Status

infructescences

Stratigraphy

Paleocene

Strat. comment

Sentinel Butte Formation

Location

near Almont, Morton County, North Dakota, USA

Paleoregion

America (North)

Data for Holotypus

Repository

Field Museum, Chicago, USA

Repository Number

PP34080

Num

fig. 16A

Pub.

A preliminary survey of fossil leaves and well-preserved reproductive structures from the Sentinel Butte Formation (Paleocene) near Almont, North Dakota [1990/12]

Data for Paratypus

Repository

Field Museum, Chicago, USA

Repository Number

PP34462 (fig. 1A), PP34085 (fig. 1E), 34100 (fig. 1F), UF 15722-15501, 15502, 15503, 15511 (fig. 1C), 15517, 15523, 15524 (fig. 1D), 15525, 15785, 15795, and 15822; UF 18907-34515 (fig. 1G, 1H)

Diagnosis

Infructescence elongate, 7–11 cm long and 3–4 cm wide including bracts, composed of many (ca. 15) cymules helically arranged around a woody axis 1.0–2.8 mm in diameter; cymules each containing paired fruits. Fruit a small, sessile nut, typically 6–6.5 mm long 3 4–5 mm wide (occasionally up to 9 mm long 3 8 mm wide), broad, and 3.5–4 mm thick, enclosed by involucre of two equal-sized, opposite bracts. Bracts large, chartaceous, 17–24 mm long, 12–19 mm wide, variable in size and marginal dissection, usually deeply dissected, bilobed, each lobe irregularly toothed or with planated spines. Nut developing from bilocular ovary, remaining bilocular, or becoming unilocular at maturity by rupture of the thin median septum. Ovules two, placentation apical, axile, with one or both developing into a seed. Nut formed from inferior ovary, oval in face view, lenticular in cross section with about 15 longitudinal ribs. Dorsal and ventral inner surfaces of the endocarp with a slight median ridge corresponding to position of the septum. Fruit wall 0.3–0.6 mm thick; endocarp 12–15 cells thick, composed of more or less isodiametric sclereids with undulating walls. Outermost layer of sclereids includes occasional idioblasts. ‘‘Mesocarp’’ of isodiametric to tangentially elongate parenchyma cells, eight cells thick, vascularized with about 15 longitudinal veins of the perianth; exocarp of sclereids. Tepals basally connate, free near nut apex. Style base single, persistent, up to 1 mm long with two stigmatic arms.