Bonatea Willd. (Orchidaceae: Habernariinae) is a small genus confined
to the African continent and Arabia. Phylogenetic and morphometric
analyses were undertaken in order to evaluate phylogenetic
relationships and species delimitations within Bonatea. In the
phylogenetic analyses, little congruence was found between ITS and
matK molecular data, while morphological results were largely
congruent with those of the ITS region. There is little sequence
variation within and between Bonatea species, which could indicate a
recent and rapid radiation. The generic characters for Bonatea were reevaluated.
Bonatea is closely related to Habenaria but differs in having
a galeate middle rostellum lobe that is clearly separated from the
vertical anther thecae. By contrast, species of Habenaria have short
anthers that are slightly arcuate and flank the rostellum. Morphometric
analyses were used to determine taxon boundaries within the Bonatea
speciosa and Bonatea cassidea complexes, respectively. Principle
component and cluster analyses of morphological variation support the
recognition of Bonatea antennifera Rolfe, Bonatea boltonii (Harv.) Bolus
and Bonatea speciosa (L.f.) Willd. as distinct species. Morphological
evidence supports the inclusion of Bonatea porrecta (Bolus) Summerh.
and Bonatea volkensiana (Kraenzl.) Rolfe in the B. speciosa c1ade and
this is corroborated by molecular data for the former. Clinal variation in
petal lobe dimensions and colour across the distribution range of
Bonatea cassidea Sond. encompasses the taxon Bonatea saundersiae
(Harv.) T.Durand & Schinz, which is reduced to synonymy. Bonatea
saundersioides (Kraenzl. & Schltr.) Cortesi, the sister species to B.
cassidea, also exhibits colour variation in its petals. A revision of
Bonatea is presented recognizing 14 species. Bonatea eminii (Kraenzl.)
Rolfe was excluded due to insufficient information. Full descriptions are
provided with diagnostic characters and distributional maps. Bonatea
bracteata G.McDonald & McMurtry and Bonatea tentaculifera Summerh.
are removed from Bonatea based on their rostellum structure which is
inconsistent with the revised generic concept. Bonatea bracteata was
transferred as Habenaria transvaalensis Schltr. and B. tentaculifera was
renamed Habenaria bonateoides M.Ponsie, as the specific epithet is
currently occupied within Habenaria. / Thesis (M.Sc.)-University of KwaZulu-Natal, 2006.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:ukzn/oai:http://researchspace.ukzn.ac.za:10413/4720 |
| Date | January 2006 |
| Creators | Ponsie, Mariaan E. |
| Contributors | Johnson, Steven D., Mitchell, Andrew. |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | English |
| Type | Thesis |
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