Anatomy of the Dicotyledons.
About: This article is published in American Midland Naturalist.The article was published on 1950-11-01. It has received 2511 citations till now.
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TL;DR: The presence of epicuticular wax on Gomphrena spp.
Abstract: The leaf structure and micromorphology characterize plant species and reflex its interactions with the environment. Leaf epidermis sculptures aid high transpiration plants on light reflection. The form and distribution of epicuticular wax crystalloids are important to characterize the surface. Aiming to know the micromorphology and the ultrastructure of G. arborescens, G. pohlii and G. virgata, leaves of these Cerrado native species were collected in Brasilia, Distrito Federal, Brazil, at the Olympic Center of the Universidade de Brasilia and at Reserva Ecologica do Roncador. Leaves of G. globosa, an Indian native species, were also studied for comparison. Leaves were fractionated, fixed and treated for observation under optical and scanning electron microscope. A description of the leaf epidermis is provided, along with some quantitative data to help the species taxonomy and support future studies on their physiology: all species are amphistomatic and have Stomatal Index between 7.27 and 18.99. The Gomphrena spp. studied have epicuticular wax platelets and wax sculptures over their larger trichome, which are relevant for their taxonomy. Over the Cerrado species cuticle, epicuticular wax is damaged by fungi hyphae development. The presence of epicuticular wax on Gomphrena spp. leaves corroborates the phylogenetical alliance between Amaranthaceae and Chenopodiaceae.
22 citations
TL;DR: A fossil leaf compression from the Late Oligocene of northwestern Ethiopia is the earliest record of the African endemic moist tropical forest genus Cola and is considered to be very similar to two extant Guineo-Congolian species but differences warrant designation of a new species.
Abstract: A fossil leaf compression from the Late Oligocene (28–27 Ma) of northwestern Ethiopia is the earliest record of the African endemic moist tropical forest genus Cola (Malvaceae sensu lato: Sterculioideae). Based on leaf and epidermal morphology, the fossil is considered to be very similar to two extant Guineo-Congolian species but differences warrant designation of a new species. This study also includes a review of the fossil record of Cola, a comprehensive summary of leaf characteristics within several extant species of Cola, Octolobus, and Pterygota, and a brief discussion of the paleogeographic implications of the fossil species affinity and occurrence in Ethiopia.
22 citations
01 Jan 2017
TL;DR: The present chapter provides detailed descriptions of morphological and anatomical characters of various parts of C. sativa plant and illustrated with bright-field and scanning electron micrographs.
Abstract: Cannabis sativa is a complex species with highly variable morphological features The present chapter provides detailed descriptions of morphological and anatomical characters of various parts of C sativa plant and illustrated with bright-field and scanning electron micrographs Male and female flowers occur in separate plants Three types of glandular trichomes namely, glandular stalked, glandular sessile and bulbous glandular trichomes are found Of these, glandular stalked trichomes are restricted to the floral bracts in pistillate plants and anthers in staminate plants The other two types of glandular trichomes are found in various parts including bracts, leaves, stems and petioles Two types of non-glandular trichomes namely, cystolith trichomes and slender covering trichomes, are present Cystolith trichomes are primarily found on the adaxial leaf surface while the covering trichomes are commonly present on the abaxial leaf surface, stems, petioles and tepals Cystolith crystals of calcium carbonate and cluster crystals of calcium oxalate are observed in the leaves Anatomical features of various parts of the plant are described and illustrated
22 citations
TL;DR: Phylogenetic analyses provide moderate support for a sister group relationship between Thomandersiaceae and Schlegeliaceae, and a new taxonomic treatment of six species is described and six species are recognized.
Abstract: The taxonomy and phylogenetic position of Thomandersia were investigated through a comprehensive study of herbarium specimens and analyses of DNA sequence and non-sequence data. Phylogenetic analysis of all available evidence placed Thomandersia within Lamiales but outside Acanthaceae, the family in which it has traditionally been classified. Moreover, Thomandersia is shown to be a morphologically distinct clade, lying outside all currently circumscribed families of Lamiales. We therefore propose resurrection of family Thomandersiaceae. Phylogenetic analyses provide moderate support for a sister group relationship between Thomandersiaceae and Schlegeliaceae. In addition, the morphological variation within and between species is described and six species are recognized. A new taxonomic treatment of these six species, including an improved key, descriptions, illustrations and distribution maps, is provided.
22 citations
TL;DR: A comparative account is given of the anatomy of 28 species, three varieties and one hybrid of the Central and South American genus Escallonia Mutis ex L.f. (classified variously in the Saxifragaceae, Escalloniaceae or Grossulariaceae).
22 citations