The taxonomic significance of anatomical characters of the stem in the southern African species of Canthium s.l. (Rubiaceae)

Tilney, P.M.; Wyk, A.E. van; Kok, P.D.F.

doi:10.1016/s0254-6299(16)31258-3

Cited by 10 publications

(8 citation statements)

References 7 publications

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“…mundianum was collected in South Africa. Based on domatia and other macromorphological characters it seems closely related to C. mundianum, but diers in having an abnormal leaf shape (broader, size up to 8.5´6.0 cm) and an almost complete lack of tanniniferous cells (see Tilney et al 1988Tilney et al , 1990 for a discussion on tanniniferous cells in southern African Vanguerieae). Whether the specimen is a new species, subspecies, or if the variation is just dependent on growth conditions is not known, but it was decided that it remains in the study awaiting a better determination.…”

Section: Discussionmentioning

confidence: 97%

Nuclear rDNA ITS sequence data used to construct the first phylogeny of Vanguerieae (Rubiaceae)

Lantz

Andreasen

Bremer

2002

Plant Systematics and Evolution

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The morphologically homogenous tribe Vanguerieae was investigated phylogenetically using sequence data from the Internal Transcribed Spacer (ITS) region in the nuclear ribosomal DNA. Sequences from 41 Vanguerieae species representing 19 genera were produced, and a parsimony analysis was performed. The phylogenetic analysis has several clades with strong support, among which three new informal groups are discussed, i.e. the Vangueria group, the Fadogia-Rytigynia group and the Spiny group. Also found monophyletic with strong support are Multidentia, Keetia, Lagynias, and Pyrostria. Canthium and Rytigynia are revealed as polyphyletic; Vangueria, Tapiphyllum, and Fadogia are paraphyletic. Results from this ®rst phylogenetic analysis of the tribe clearly demonstrate a need for new circumscriptions of several genera. Morphological characters are discussed and putative synapomorphies are mentioned. Jackknife, bootstrap, and Bremer support are calculated and dierences found in support are discussed.

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Section: Discussionmentioning

confidence: 97%

Nuclear rDNA ITS sequence data used to construct the first phylogeny of Vanguerieae (Rubiaceae)

Lantz

Andreasen

Bremer

2002

Plant Systematics and Evolution

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“…When comparing species, hairs can have a varying number of cells, different colour and variable length. Unicellular hairs are only found in Psydrax (Tilney, van Wyk & Kok, 1988; Tilney, Kok & van Wyk, 1990). This distinction between unicellular and multicellular hairs is the only clear distinction we can make when looking at the variation present in the whole tribe.…”

Section: Discussionmentioning

confidence: 99%

“…Given this lack of information, we code only for supra‐axillary spines and not for any other type. Spines are also known from Rytigynia subgenus Rytigynia , a few South African Canthium species not placed to subgenus (Tilney, 1986; Bridson, 1992), and several south‐east Asian Canthium species (Wong, 1989).…”

Section: Discussionmentioning

confidence: 99%

Phylogeny inferred from morphology and DNA data: characterizing well-supported groups in Vanguerieae (Rubiaceae)

Lantz

Bremer

2004

Botanical Journal of the Linnean Society

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The Vanguerieae is a species-rich tribe of the Rubiaceae with problematic generic circumscriptions. Here we address this issue by presenting a phylogeny in which strongly supported groups are identified. We use DNA sequence data from the nuclear ribosomal internal transcribed spacer (ITS) region, trnT-F sequences from the chloroplast genome, and 30 morphological characters. Over 70 taxa are sampled, representing 23 out of the 27 currently recognized genera. We also present a detailed discussion of the morphological variation present in the tribe, in which we focus on features that are taxonomically informative. We show that there are several strongly supported groups in the tribe, but that these rarely coincide with traditional genera. Canthium, Rytigynia, Tapiphyllum and possibly Pygmaeothamnus are polyphyletic, and Fadogia is paraphyletic. Keetia, Lagynias, and Multidentia are monophyletic with strong support, while the monophyly of Psydrax is weakly supported. Several morphological characters are mapped onto the phylogeny to visualize how these can be used to delimit monophyletic groups. Canthium subgenus Afrocanthium is given generic rank as Afrocanthium and 17 combinations for species in this genus are made. New combinations are also made for Canthium sensu stricto.

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“…into several genera on the basis of morphological characters, a decision which contradicted the ideas of Verdcourt. The division of the large Canthium complex was also supported by Tilney et al (1988) who studied anatomical characters of young stems.…”

Section: Introductionmentioning

confidence: 85%

Wood Anatomy of the Vanguerieae (Ixoroideaerubiaceae), With Special Emphasis on Some Geofrutices

Lens¹,

Jansen²,

Robbrecht³

et al. 2000

IAWA J

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SUMMARYThe Vanguerieae is a tribe consisting of about 500 species ordered in 27 genera. Although this tribe is mainly represented in Africa and Madagascar, Vanguerieae also occur in tropical Asia, Australia, and the isles of the Pacific Ocean. This study gives a detailed wood anatomical description of 34 species of 15 genera based on LM and SEM observations. The secondary xylem is homogeneous throughout the tribe and fits well into the Ixoroideae s.l. on the basis of fibre-tracheids and diffuse to diffuse-in-aggregates axial parenchyma. The Vanguerieae include numerous geofrutices that are characterised by massive woody branched or unbranched underground parts and slightly ramified unbranched aboveground twigs. The underground structures of geofrutices are not homologous; a central pith is found in three species (Fadogia schmitzii, Pygmaeothamnus zeyheri and Tapiphyllum cinerascens var. laetum), while Fadogiella stigmatoloba shows central primary xylem which is characteristic of roots. Comparison of underground versus aboveground wood shows anatomical differences in vessel diameter and in the quantity of parenchyma and fibres.

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The taxonomic significance of anatomical characters of the stem in the southern African species of Canthium s.l. (Rubiaceae)

Cited by 10 publications

References 7 publications

Nuclear rDNA ITS sequence data used to construct the first phylogeny of Vanguerieae (Rubiaceae)

Nuclear rDNA ITS sequence data used to construct the first phylogeny of Vanguerieae (Rubiaceae)

Phylogeny inferred from morphology and DNA data: characterizing well-supported groups in Vanguerieae (Rubiaceae)

Wood Anatomy of the Vanguerieae (Ixoroideaerubiaceae), With Special Emphasis on Some Geofrutices

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