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Mesoxylon priapi
Mesoxylon priapi Trivett, G.W. Rothwell Syst. Bot., 10(2): 209. 21 May 1985
- Name
- Mesoxylon priapi
- Rank
- Species
- Generic Name
- [Genus] Mesoxylon
- Authors (Pub.)
- Trivett M. L.
Rothwell G. W.
- Publication
- Morphology, systematics, and paleoecology of Paleozoic fossil plants: Mesoxylon priapi, sp. nov. (Cordaitales) [1985/5]
- Journal
- Systematic Botany
- Volume
- 10
- Issue
- 2
- Page number
- 209
- Year
- 1985
- Fossil Status
- leafy stems (with reproductive organs)
- Stratigraphy
- Kasimovian
- Strat. comment
- Conemaugh Group
- Location
- south side of Ohio Route 22 (Wayne Township, Smithfield Quadrangle), ca. 8 km west of Steubenville, Jefferson Co., Ohio, USA
- Paleoregion
- Laurussia (Laurentia)
Data for Holotypus
- Repository
- Field Museum, Chicago, USA
- Repository Number
- OUPH nos. 7259-7262 and 7273-7310 [Coal Ball 756]
- Diagnosis
- Stems with non-septate, parenchymatous pith; leaves approaching an 8/21 phyllotaxis on some stems; leaf traces di- verging from margin ofpith as two bundles. Leaves up to 5.7 -cm wide and 1 mm thick with bluntly rounded margins, comparable to Cor- daites felicis. Branching axillary with one vege- tative bud, one cone, or one bud and one cone at some nodes. Traces to paired branches orig- inating by division of a single stele in stem cortex. Cones compound, consisting of elon- gate, rectangular primary axis (ca. 1-2 mm x 4-5 mm) bearing numerous, alternately ar- ranged four-ranked bracts subtending second- ary axes. Stele of primary axis rectangular in cross section, having narrow pith and a narrow band of randomly arranged tracheids sur- rounded by radially aligned tracheids. Cortex two-parted; inner zone of large and small parenchyma cells interspersed with resin or se- cretory cells with dark contents, and outer hypodermal zone of small, dark, thin-walled cells. Surface of axis irregularly striate. Second- ary axes approximately 1 mm wide x 4 mm long, radially symmetrical, bearing up to 28 he- lically arranged scales; fertile scales (?5) api- cal-most and typically bearing four pollen sacs in linear file at tip. Pollen sacs maturing si- multaneously and containing Sullisaccites-type prepollen (ca. 75 ,um x 95 ,um). Basal sterile scales of secondary axes imbricating tightly to ensheath completely fertile apex prior to ma- turity; at maturity, fertile scales elongated, extending pollen sacs beyond tips of sterile scales.
