SYNOPTIC DESCRIPTION OF THE PHYLUM ANTHOCEROTOPHYTA
| EUKARYA> ARCHAEPLASTIDA> VIRIDIPLANTAE> STREPTOBIONTA> EMBRYOPHYTA> ANTHOCEROTOPHYTA |
ANTHOCEROTOPHYTA LINKS
| The following description came from Margulis and Schwartz (1998), Bold et al. (1987), and Schofield (1985). |
I. SYNONYMS: hornworts, Anthocerotes.
II. NUMBER: >100 species
III. PHYLUM CHARACTERISTICS
- A. Gametophyte
- Form: Thallose; tissue undifferentiated.
- Rhizoids: Rhizoids (text with tooltip) Thread-like growths, simple or branched, which serve for absorption and anchorage. simple, no scales.
- Stomata: Present with two guard cells; open into mucilage-filled cavities.
- Chloroplasts: One large chloroplast per cell, pyrenoids present.
- Gametangia: Develop from internal cells. Gametangiophores absent.
- Protonemata: Absent.
- B. Sporophyte
- Form: With foot (text with tooltip) A foot is the muscular locomotory organ whose structure defines, in part, the molluscan classes. , intercalary meristem (text with tooltip) A meristemic region located between two partly differentiated tissue regions. and elongate capsule (text with tooltip) The sporangium of the sporophyte; elevated by the seta. ; indeterminate growth (text with tooltip) Having the capacity for continuous growth at the apex. ; with chloroplasts and stomates (text with tooltip) Pores in the leaf epidermis surrounded by a pair of guard cells. The gas exchange of leaves is controlled by the dimension of the pores. .
- Seta: Absent.
- Capsule: Contains much sterile tissue; columella (text with tooltip) A small column of tissue running up through the center of the capsule. present; dehisces (text with tooltip) To split open releasing spores. along 2 lines.
- Elaters: Present.
- Calyptra: Absent.
- Peristome: Absent.
- Anatomy and Life History of the Hornworts
- C. Ecology: These plants are found throughout the world particularly in milder climates; some are tropical. Usually they occur attached on shaded, humid soil.
| LITERATURE CITED Bold, H. C., C. J. Alexopoulos, and T. Delevoryas. 1987. Morphology of Plants and Fungi. 5th Edition. HarperCollins Publishers, Inc. New York. Crandall-Stotler, B. J., R. E. Stotler, W. T. Doyle, and L. L. Forrest. 2008. Phaeoceros proskaueri sp. nov, a new species of the Phaeoceros hallii (Austin) Prosk. –Phaeoceros pearsonii (M. Howe) Prosk. Complex and the systematic affinities of Paraphymatoceros Hassel. Fieldiana: Botany, N.S. 47: 213-238. Dittmer, H. J. 1964. Phylogeny and Form in the Plant Kingdom. Van Norstrand Company, Inc. New York. Duff, R. J. 2006. Divergent RNA editing frequencies in hornwort mitochondrial nad5 sequences. Gene. 366: 285-291. Frey, W. and M. Stech. 2005. A morpho-molecular classification of the Anthocerotophyta (hornworts). Nova Hedwigia. 80 (3-4): 541-545. Margulis, L. and K. Schwartz. 1998. Five kingdoms, an illustrated guide to the phyla of life on earth. 3rd Edition. W. H. Freeman and Company. New York. Marin, B. and M. Melkonian. 1999. Mesostigmatophyceae, a new class of streptophyte green algae revealed by SSU rRNA sequence comparisons. Protist. 150: 399-417. Pena, M. J., A. G. Darvill, S. Eberhard, W. S. York, and M. A. O’Neill. 2008. Moss and liverowrt xyloglycans contain galacturonic acids and are structurally distinct from the xyloglycans synthesized by hornworts and vascular plants. Glycobiology. 18(11): 891-904. Renzaglia, K. S. 1978. A comparative morphology and developmental anatomy of the Anthocerotophyta. Journal of the Hattori Botanical Laboratory. 44: 31–90. Scagel, R. F., R. J. Bandoni, J. R. Maze, G. E. Rouse, W.B. Schofield, and J. R. Stein. 1982. Nonvascular Plants. Wadsworth Publishing Co., Belmont, California. Schofield, W. B. 1985. Introduction to Bryology. Macmillan Publishing Co. New York. Shaw, J. and K. Renzaglia. 2004. Phylogeny and diversification of bryophytes. American Journal of Botany. 91(10): 1557-1581. Stotler, R. E. and B. Crandall-Stotler. 2005. A revised classification of Anthocerotophyta and a checklist of the hornworts of North America, north of Mexico. The Bryologist. 108(1): 16-26. |
| By Jack R. Holt. Last revised: 03/20/2013 |
