A functional evolution of the Leucobryaceae
- Recent conclusions on the limits of the Leucobryaceae and on the function of the Leucobryaceous leaf are used as basis for further observations on evolution of the group. Eight genera are recognized in the family; 1. Leucobryum, 2. Steyermarkiella, 3. Ochrobryum, 4. Arthrocormus, 5. Schistomitrium, 6. Holomitriopsis, 7. Cladopodanthus, and 8. Octoblepharum. The leaf form, capsule shape, and peristome substructure of Leucobryum seems to derive from a Campylopus-type member of the Dicranaceae. Four basic stages are noted in the functional evolution of the family. 1. The stratification of the leaf into leucocysts and chlorocyst layers with leucocysts holding water and internally generated gas; 2. The shift from soil substrates seen mostly in Temperate Zone Leucobryum to rotten wood substrates or epiphytism; 3. Increasing reliance on vegetative reproduction with reduction of reliance on sporophytes; 4. Morphogenetic increase of the number of chlorocysts in the leaf. Geographical concentrations of the genera are noted, and distributions between hemispheres are apparently mostly by way of the South Atlantic. The use of functional considerations in evolutionary studies is emphasized. The retention of paraphyletic groups in taxonomy is defended.
Author: | Harold Robinson |
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URN: | urn:nbn:de:hebis:30:3-301799 |
ISSN: | 0935-5626 |
Parent Title (English): | Tropical bryology |
Publisher: | D. Quandt, Univ. Bonn, Nees Inst. für Biodiversität d. Pflanzen |
Place of publication: | Bonn |
Document Type: | Article |
Language: | English |
Year of Completion: | 1990 |
Year of first Publication: | 1990 |
Publishing Institution: | Universitätsbibliothek Johann Christian Senckenberg |
Release Date: | 2013/07/05 |
Volume: | 2 |
Page Number: | 15 |
First Page: | 223 |
Last Page: | 237 |
Note: | The layout of the electronic version of this contribution differs from the layout of the original version published in the printed volume. |
HeBIS-PPN: | 347431933 |
Dewey Decimal Classification: | 5 Naturwissenschaften und Mathematik / 58 Pflanzen (Botanik) / 580 Pflanzen (Botanik) |
Sammlungen: | Sammlung Biologie / Sondersammelgebiets-Volltexte |
Zeitschriften / Jahresberichte: | Tropical Bryology / Tropical Bryology, Volume 2 (1990) |
: | urn:nbn:de:hebis:30:3-301345 |
Licence (German): | Deutsches Urheberrecht |