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Arachnoxylon minus
Arachnoxylon minus W.E. Stein, D. Wight, C.B. Beck Canad. J. Bot., 61(4): 1298. 6 May 1983
- Name
- Arachnoxylon minus
- Rank
- Species
- Original spelling
- minor
- Generic Name
- [Genus] Arachnoxylon
- Authors (Pub.)
- Stein W. E.
Wight D. C.
Beck C. B.
- Publication
- Arachnoxylon from the Middle Devonian of southwestern Virginia [1983/5]
- Journal
- Canadian Journal of Botany
- Volume
- 61
- Issue
- 4
- Page number
- 1298
- Year
- 1983
- Fossil Status
- stems (wood)
- Stratigraphy
- Eifelian
- Strat. comment
- Purcell Member of the Millboro Shale Formation
- Location
- United States Route 11, 1 mi E. of Radford, Montgomery County, Virginia, USA
- Paleoregion
- Laurussia (Laurentia)
Data for Holotypus
- Repository
- Museum of Palaeontology, University of Michigan, Ann Arbor, USA
- Repository Number
- 64852 [50 slides and 77 unmounted preparations]
- Diagnosis
- Axes from 3 to 6 mm in diameter, cortical cells elongate, 50 to 120 pm in diameter. Some cells with dark materials in their lumina. Primary xylem X or H shaped, 1.6 to 4.0 mm in diameter along a diagonal, with a total of four or five protoxylem strands. Individual primary xylem ribs from 0.2 to 0.9mm in width. Protoxylem or early metaxylem tracheids from 12 to 25 pm in diameter. Large metaxylem tracheids from 25 to 100 pm in diameter. Primary xylem of minor trace 0.17 to 0.21 mm in diameter proximally, becoming tangentially elongate below level of division. Primary xylem of major trace 1.5 mm tangentially by 0.44 mm radially near level of departure, 1.2 by 0.5 mm at the base of a lateral appendage which it supplies, and 0.4 by 0.5 mm approximately 1 cm from the base within this lateral appendage. Epidermis a single layer of cells with pockets or longitudinal grooves in the surface of the axis as much as 0.2 mm deep. Multicellular superficial emergences, consisting of both epidermis and cortical tissues, 0.2 to 0.3 mm in diameter. Some emergences borne from inside the grooves at right angles to the axis.
