| EUKARYA> ARCHAEPLASTIDA> VIRIDIPLANTAE> STREPTOBIONTA> EMBRYOPHYTA> TRACHEOPHYTA> TRIMEROPHYTOPHYTA |
TRIMEROPHYTOPHYTA LINKS
| The following description came from Bold et al. (1987) and Bierhorst (1971). |
I. SYNONYMS: trimerophytes.
II. NUMBER: all extinct.
III. PHYLUM CHARACTERISTICS
- A. Structure
- Gametophyte: Likely photosynthetic and structurally complex (Kenrick and Crane, 1997).
- Sporophyte: Herbaceous; unequally dichotomously branching (text with tooltip) Dichotomous branching is the simple pattern of branching in which each node produces two equal branches. stems. Thus, plant appears to have a central axis with smaller lateral branches.
- 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 the ends of short lateral dichotomously branched axes branches. They appear to have dehisced (text with tooltip) To split open releasing spores. longitudinally.
- Stele: A slender solid centrarch (text with tooltip) A centrarch stele is a protostele with ptimary xylem in the center. ( mesarch (text with tooltip) A mesarch (adj) stele is one in which the protoxylem forms between the center and outer part of the xylem. ?) 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 Devonian period. 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. |
| By Jack R. Holt. Last revised: 03/25/2013 |
