SYNOPTIC DESCRIPTION OF THE PHYLUM ZOSTEROPHYLLOPHYTA
| EUKARYA> ARCHAEPLASTIDA> VIRIDIPLANTAE> STREPTOBIONTA> EMBRYOPHYTA> TRACHEOPHYTA> ZOSTEROPHYLLOPHYTA |
ZOSTEROPHYLLOPHYTA LINKS
| The following description comes from Bold et al. (1987) and Bierhorst (1971). |
I. SYNONYMS:
II. NUMBER: all extinct.
III. PHYLUM CHARACTERISTICS
- A. Structure
- Gametophyte: Likely photosynthetic and structurally complex (see Kenrick and Crane, 1997).
- Sporophyte: Herbaceous; dichotomously branching (text with tooltip) Dichotomous branching is the simple pattern of branching in which each node produces two equal branches. stems usually covered with lateral spines. Circinate growth.
- Spores: Homosporous (text with tooltip) Homosporous (adj) plants produce one type of spore. .
- Sporangia: Thick-walled eusporangia (text with tooltip) A eusporangium is the most common spore-bearing structure in plants. Eusporangia develop from more than one cell and usually have a wall of several cell layers. Contrast a eusporangium with a leptosporangium. occur on short lateral stalks on the sides of the fertile stems.
- Stele: A slender solid exarch (text with tooltip) An exarch (adj) stele is one that has the protoxylem on the outside of the xylem bundle. vascular bundle.
- Leaves: Absent.
- Roots: Absent. Probably a branching rhizomatous (text with tooltip) Plants having rhizomes (horizontal stems, often underground or on the surface of the ground, bearing scale-like leaves). system with rhizoids (text with tooltip) Thread-like growths, simple or branched, which serve for absorption and anchorage. .
- B. Ecology: All plants extinct from the Silurain and Devonian periods. Fossils indicate that the plants grew in shallow aquatic habitats.
| LITERATURE CITED Banks, H. P. 1975. Reclassification of Psilophyta. Taxon. 24: 401-413. Bierhorst, D. W. 1971. Morphology of Vascular Plants. In: N. H. Giles and J. G. Torrey. The MacMillan Biology Series. The MacMillan Co. New York. Bold, H. C., C. J. Alexopoulos, and T. Delevoryas. 1987. Morphology of Plants and Fungi. 5th Edition. HarperCollins Publishers, Inc. New York. Doyle, J. A. 1998b. Phylogeny of vascular plants. Annual Review of Ecology and Systematics. 29:567-599. Kenrick, P. and P. R. Crane. 1997b. The Origin and Early Diversification of Land Plants: A Cladistic Study. Smithsonian Institute Press. Washington, DC. Northington, D. K. and J. R. Goodin. 1984. The Botanical World. Times Mirror/Mosby College Publishing, St. Louis. Zhu, W.-Q. and P. Kenrick. 1999. A Zosterophyllum-like plant from the lower Devonian of Yunnan Province, China. Review of Palaeobotany and {alynology. 105: 111-118. |
| By Jack R. Holt. Last revised: 04/09/2010 |
