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Osmunda arnoldii
Osmunda arnoldii C.N. Mill. Contr. Mus. Paleontol. Univ. Michigan, 21(8): 181. 30 Jun 1967
- Name
- Osmunda arnoldii
- Rank
- Species
- Generic Name
- [Genus] Osmunda
- Authors (Pub.)
- Miller C. N., Jr.
- Publication
- Evolution of the fern genus Osmunda [1967/6]
- Journal
- Contributions from the Museum of Paleontology, University of Michigan
- Volume
- 21
- Issue
- 8
- Page number
- 181
- Year
- 1967
- Fossil Status
- rhizomata
- Stratigraphy
- Paleocene
- Strat. comment
- Fort Union Formation
- Location
- Morton County, North Dakota, USA
- Paleoregion
- America (North)
Data for Holotypus
- Repository
- Museum of Palaeontology, University of Michigan, Ann Arbor, USA
- Repository Number
- 52161
- Diagnosis
- Petrified rhizomes about 6.0 cm. in diameter, consisting of a stem about 10 mm. in diameter surrounded by a mantle of closely adhering petiole bases; xylem cylinder of stem about 2.5 mm. in diameter, 1.0 mm. thick, and consisting of 8-12 strands as observed in transverse section; leaf-gaps high and wide, formed immediately opposite each departing leaf-trace; cortex consisting of a thin inner parenchymatous zone and a thick outer fibrous zone, together including 5-7 departing leaf- traces in a given transverse section; leaf-trace endarch, separating from the stem xylem with two protoxylems and with a pronounced curvature; petiole base stipular, containing numerous masses of sclerenchyma scattered throughout, and an elongate strip of fibers lining the concavity of the vascular strand; roots with diarch xylem strand, separating from leaf- traces as latter diverge from stem xylem.
