Table of Contents Author Guidelines Submit a Manuscript
Journal of Botany
Volume 2017 (2017), Article ID 4369029, 16 pages
Research Article

Phylogeny of Ten Kenyan Plectranthus Species in the Coleus Clade Inferred from Leaf Micromorphology, Rbcl and MatK Genes

1Department of Applied and Technical Biology, School of Biological and Life Sciences, Technical University of Kenya, P.O. Box 52428-00200, Nairobi, Kenya
2School of Biological Sciences, College of Biological and Physical Sciences, University of Nairobi, P.O. Box 30197-00100, Nairobi, Kenya
3Department of Public Health, Toxicology and Pharmacology, College of Agriculture and Veterinary Sciences, University of Nairobi, P.O. Box 29053-00625, Nairobi, Kenya

Correspondence should be addressed to Fredrick M. Musila

Received 22 July 2017; Revised 31 October 2017; Accepted 20 November 2017; Published 18 December 2017

Academic Editor: Jutta Ludwig-Müller

Copyright © 2017 Fredrick M. Musila et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Plectranthus species are difficult to taxonomically delimit due to lack of clear-cut morphological synapomorphies. This study is aimed at bringing insights into classification of ten Plectranthus species in the Coleus clade by using leaf micromorphology and molecular data. Stomatal counts and observation of microtome leaf sections generated leaf micromorphology data, while molecular data was obtained from sequencing MatK and Rbcl genes from each species. Phylogeny based on the MatK and Rbcl gene sequences clustered four species P. caninus, P. otostegioides, P. barbatus, and P. lanuginosus together (Clusters A and D, respectively), while P. pseudomarrubioides, P. ornatus, and P. aegyptiacus were grouped together into Clusters B and E, respectively, and P. montanus and P. amboinicus were grouped together (Cluster C). A dendrogram was generated through a cluster analysis of the leaf micromorphological characters grouped together, P. caninus, P. ornatus, P. otostegioides, P. montanus, and P. pseudomarrubioides (Cluster F). The dendrogram also grouped together P. aegyptiacus, P. amboinicus, P. edulis, P. barbatus, and P. lanuginosus (Cluster G). The present study has grouped the ten studied Plectranthus species using molecular and leaf micromorphology characters into phylogenies, which are supported by previous studies, and proved that these characters can aid in plant identification and phylogenetic studies.