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Zosterophyllum divaricatum
Zosterophyllum divaricatum Gensel Amer. J. Bot., 69(5): 652. 22 Jun 1982
- Name
- Zosterophyllum divaricatum
- Rank
- Species
- Generic Name
- [Genus] Zosterophyllum
- Authors (Pub.)
- Gensel P. G.
- Publication
- A new species of Zosterophyllum from the Early Devonian of New Brunswick [1982/6]
- Journal
- American Journal of Botany
- Volume
- 69
- Issue
- 5
- Page number
- 652
- Year
- 1982
- Fossil Status
- stems (with sporangia)
- Stratigraphy
- Emsian
- Strat. comment
- Gaspe Sandstone Group
- Location
- 0.8 km from Dalhousie Jct., New Brunswick, Canada
- Paleoregion
- Laurussia (Laurentia)
Data for Holotypus
- Repository
- Geological Survey of Canada, Ottawa, Canada
- Repository Number
- GSC # 65486 a, b
- Diagnosis
- Plant with smooth axes at least 14 em long, 1.0-4.0 mm wide, branching dichotomous in vegetative and fertile regions. Axes covered by a cuticle; epidermal ceIls rectangular to elongate polygonal, 100-400 JLm long and 1050 JLm wide, some being shorter in some areas (where branching occurs?). Central vascular strand composed of tracheids 10-40 JLm wide, with annular, close-annular and helical thickenings. Axes bear sporangia in sub-terminal and terminal regions above and below dichotomies. Sporangia are alternate in two rows, 90° to 180° apart, occasionally in one row, oriented to one side of the axis, borne on stalks 1.5-2.0 mm long, 1.0-1.5 mm wide; stalks inserted on axis obliquely or at right angles; straight, curved or bent 90°, often twisted around the axis. Distal part of stalk flares and forms dome-shaped structure at base of sporangium. Sporangia reniform, 2-4 mm high and wide, smaIler distaIly , composed of two equal valves with weIl-developed basal lobes, dehiscence occurring along modified distal margin. Inner sporangial wall cuticle with lozenge-shaped cells, 40-100 JLm long and 20-40 JLm wide, often with central dark papilla. Margin ceIls appear rectangular. Spores circular to subcircular, trilete, 50-90 JLm in diameter, curvaturate, smooth to slightly roughened, with dark area at juncture oftrilete rays. Surface covered with tapetal residue.
