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Journal ArticleDOI

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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Journal ArticleDOI
TL;DR: The frond architecture, variation in pinnule morphology and epidermal anatomy, palaeoecology and geographical distribution of Peltaspermum martinsii are discussed and the species is compared with other Late Permian callipterids.

86 citations

Journal ArticleDOI
TL;DR: Recent prehistoric vegetation is studied by means of char- coal found in archaeological deposits, giving evidence of steppe forests and forests directly related to late Glacial and early Postglacial climatic environments.
Abstract: Recent prehistoric vegetation is studied by means of char- coal found in archaeological deposits. Such charcoal is the direct result of interaction between man and the plant environment because it comes from wood cut by man himself. Abundant samples allow us to establish a biostratigraphy in the northwestern Mediterranean area. The results are compared with pollen analyses. Four stages are described, the first begin- ning 10,000 years ago. Stages 1 and 2 give evidence of steppe forests and forests directly related to late Glacial and early Postglacial climatic

86 citations

Journal ArticleDOI
TL;DR: In search for the sister group of the Asteraceae, morphological evidence was assembled for investigating the relationship between the Aster Families and those families most frequently considered to be sister groups.
Abstract: In search for the sister group of the Asteraceae, morphological evidence was assembled for investigating the relationship between the Asteraceae and those families most frequently considered to be ...

86 citations

Journal ArticleDOI
TL;DR: A morphometric estimation of leucoplast development in the cells suggested a quantitative relationship between the expansion of this plastidome and the ratio of monoterpenes in the oil....
Abstract: Analytical and structural studies were performed on 45 species of higher plants containing specialized secretory structures and/or producing essential oils or resins. Significant amounts of volatile compounds, mainly monoterpenes and sesquiterpenes, were recovered from these species. The specialized structures included glandular hairs, resin ducts, secretory cavities and idioblasts. During the ultrastructural investigation, special attention was paid to the plastidome. A number of secretory cells contain true leucoplasts, devoid of thylakoids and ribosomes. The comparison between analytical and structural data showed a very close correlation between the presence of leucoplasts in secretory cells and the significant quantities of monoterpenes (hydrocarbons or oxygenated compounds) in the volatile extract. Moreover, a morphometric estimation of leucoplast development in the cells suggested a quantitative relationship between the expansion of this plastidome and the ratio of monoterpenes in the oil....

84 citations

Journal ArticleDOI
TL;DR: A model based on the extant cool temperate Valdivian rainforests is proposed and ecological reconstructions based on palaeobotanical and geological evidence suggest that changes in the palaeovegetation reflect natural dynamics following volcanic disturbances.

83 citations