Thesis (MSc)--Stellenbosch University, 2004. / ENGLISH ABSTRACT: The systematics of the southern African members of the genus Oxalis L. (Oxalidaceae) is in a
state of flux. The bulbs of these species contain potential taxonomically important characters
and therefore require detailed study (Salter, 1944). A pilot study assessed the homology of
bulbs among southern African Oxalis species (Gebregziabher, 2001), and found that they are
all homologous structures. This pilot study also emphasized the range of potentially
informative characters from different bulb parts.
The aim of the present study was to assess the taxonomic significance of bulb morphology in
selected southern African Oxalis species. As far as possible, efforts were made to represent
both the taxonomic (Salter, 1944) and palynological diversity (Dreyer, 1996) present in the
genus.
Detailed bulb morphological studies of 30 species of southern African Oxalis species revealed
41 potentially informative characters. Different bulb-types were identified based on these
characters. Bulb-type affinities of taxa included in this study, as well as bulb descriptions
from the pilot study (Gebregziabher, 2001), were discussed. Comparison with the current
taxonomic classification (Salter, 1944), palynological classification (Dreyer, 1996) and a
preliminary phylogeny based on the non-coding plastid trnL-trnF DNA region (Oberlander,
2003), were also made. Bulb morphology conflicted with the current taxonomic classification
(Salter, 1944), but showed greater congruence with both the palynological groupings and the
trnL-trnF based phylogeny.
Based on this study, bulb morphology is found to be taxonomically significant. Further
studies on the bulb morphology and anatomy of southern African Oxalis species are merited.
Key words: bulb morphology, Oxalis, informative characters, basal plates, fleshy leaves,
tunics / AFRIKAANSE OPSOMMING: Die sistematiek van die suider Afrikaanse lede van Oxalis L. (Oxalidaceae) is labiel. Die bolle
van hierdie spesies sluit potensieel taksonomies belangrike kenmerke in, en behoort daarom in
detail bestudeer te word (Salter, 1944). In Loodsstudie het die homologie van die bolle van die
suider Afrikaanse Oxalis spesies ge-evalueer (Gebregziabher, 2001), en gevind dat hulle
homoloë strukture is. Resultate van hierdie loodsstudie het ook die reeks van potensieel
informatiewe kenmerke van verskillende boldele beklemtoon.
Die doel van hierdie studie was om die taksonomiese belang van boImorfologie in
geselekteerde suider Afrikaanse Oxalis spesies te ondersoek. Pogings is aangewend om, sover
moontlik, beide die taksonomiese (Salter, 1944) en die palinologiese (Dreyer, 1996)
diversiteit van die genus in die studie in te sluit.
Gedetailleerde bol-morfologiese studies van 30 suider Afrikaanse Oxalis spesies het 41
potensieel informatiewe kenmerke uitgewys. Gebaseer op hierdie kenmerke, is verskillende
bol-tipes geïdentifiseer. Verwantskappe tussen die bol-tipes van die spesies ingesluit in
hierdie studie, sowel as beskrywings van bolle volgens die loodsstudie (Gebregziabher, 2001),
word bespreek. Vergelykings met die huidige taksonomiese klassifikasie (Salter, 1944),
palinologiese klassifikasie (Dreyer, 1996) en In voorlopige filogenie gebaseer op die niekoderende
plastied trnL-F DNA-streek (Oberlander, 2003) is ook getref. BoImorfologie
weerspreek die huidige taksonomiese klassifikasie (Salter, 1944), maar toon groter
ooreenstemming met beide die palinologiese groeperings en die trnL-F gebaseerde filogenie.
Hierdie studie het bevind dat bolmorfologie van taksonomiese waarde is. Verdere studies op
die bolmorfologie en -anatomie van die suider Afrikaanse Oxalis spesies word aanbeveel.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/53762 |
| Date | 12 1900 |
| Creators | Gebregziabher, Awot Kiflu |
| Contributors | Dreyer, L. L., Marais, E. M., Stellenbosch University. Faculty of Science. Dept. of Botany and Zoology. |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | English |
| Type | Thesis |
| Format | 120 p. : ill. |
| Rights | Stellenbosch University |
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