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Wilfrid Laurier University

Morphology

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Full-Text Articles in Biology

Evolutionary History And Taxonomy Of The Cuscuta Umbellata Complex (Convolvulaceae): Evidence Of Extensive Hybridization From Discordant Nuclear And Plastid Phylogenies, Mihai Costea, Saša Stefanović Oct 2010

Evolutionary History And Taxonomy Of The Cuscuta Umbellata Complex (Convolvulaceae): Evidence Of Extensive Hybridization From Discordant Nuclear And Plastid Phylogenies, Mihai Costea, Saša Stefanović

Biology Faculty Publications

The Cuscuta umbellata complex is one of the 15 major clades recently circumscribed in C. subg. Grammica. Most of its members occur in North AMerican and the Caribbean (C. desmouliniana, C. lacerata, C. lacerata, C. leptantha, C. liliputana, C. odontolepsis, C. polyanthemos, C. tuberculata, C. umbellata), but three species (C. acuta, C. membranacea, C. umbellata) grow in South America, and one (C. hyalina) is found as a native species in India, Pakistan and Eastern to South Africa. Basic morphology, scanning electron microscopy and …


Stem Morphology And Anatomy In Amaranthus L. (Amaranthaceae)—Taxonomic Significance, Mihai Costea, Darleen A. Demason Sep 2001

Stem Morphology And Anatomy In Amaranthus L. (Amaranthaceae)—Taxonomic Significance, Mihai Costea, Darleen A. Demason

Biology Faculty Publications

The range of variation within the genus Amaranthus L. (Amaranthaceae) is described for a number of stem characters including: morphology, epidermis, primary stem vasculature and mechanism of secondary growth. The results provide new characters (phyllotaxy, complexity of leaf vascular supply and relative amount of secondary growth) that support (1) a new infrageneric classification (subgenus Amaranthus vs subgenus Albersia (Kunth)Gren. & Dodr.), and (2) the separation within the “hybridus” complex of cultivated amaranths (A. caudatus L., A. cruentus L., and A. hypochondriacus L.) from their presumed wild ancestors (A. hybridus L. subsp. quitensis (Kunth) Costea & Carretero, …