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: Analysis of character evolution suggests that the ancestral condition of angiosperms can be described as anomo-stephanocytic, a system in which complexes lacking subdidiaries (anomocytic) intergrade with those having weakly differentiated subsidiaries arranged in a rosette (stepanocytic).
Abstract: Stomatal architecture—the number, form, and arrangement of specialized epidermal cells associated with stomatal guard cells—of 46 species of basal angiosperms representing all ANITA grade families and Chloranthaceae was investigated. Leaf clearings and cuticular preparations were examined with light microscopy, and a sample of 100 stomata from each specimen was coded for stomatal type and five other characters contributing to stomatal architecture. New stomatal types were defined, and many species were examined and illustrated for the first time. Character evolution was examined in light of the ANITA hypothesis using MacClade software. Analysis of character evolution, along with other evidence from this study and evidence from the literature on fossil angiosperms and other seed plant lineages, suggests that the ancestral condition of angiosperms can be described as anomo-stephanocytic, a system in which complexes lacking subdidiaries (anomocytic) intergrade with those having weakly differentiated subsidiaries arranged in a rosette (stephanocytic). From this ancestral condition, tangential divisions of contact cells led to the profusion of different types seen in early fossil angiosperms and Amborellaceae, Austrobaileyales, and derived Chloranthaceae, while the state in Nymphaeales is little modified. Formation of new, derived types by tangential division appears to be a recurrent theme in seed plant evolution.
114 citations
TL;DR: Wood anatomy provides characters that are of potential phylogenetic utility at a variety of levels of relationship and the most likely sister taxon to Moringa is Cylicomorpha (Caricaceae).
113 citations
TL;DR: Recent advances in wood physiology, molecular phylogeny, and ultrastructure (chiefly scanning electron microscopy, SEM), as well as important new knowledge in traditional fields, provide the basis for a new vision of how wood evolves.
Abstract: Recent advances in wood physiology, molecular phylogeny, and ultrastructure (chiefly scanning electron microscopy, SEM), as well as important new knowledge in traditional fields, provide the basis ...
113 citations
Cites background from "Anatomy of the Dicotyledons."
...In wet forest trees, an average vessel diameter of 100 μm is not unusual (Metcalfe and Chalk 1950)....
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TL;DR: Similarities among taxa of glucosinolate-producing plants and putative relatives were evaluated using numerical methods applied to a dataset of 93 characters, revealing considerable complexity, hence little redundancy in this dataset.
Abstract: Similarities among taxa of glucosinolate-producing plants and putative relatives were evaluated using numerical methods applied to a dataset of 93 characters. These include anatomical and morphologica
111 citations
TL;DR: The varied appearances of each of these tissues in genera that have successive cambia is discussed, and themes that particular genera represent are examined: storage and retrieval; promotion of mechanical strength and longevity of vascular tissues; and modes of lianoid structure.
Abstract: Plant anatomists are generally agreed on the histological products of successive cambia: bands of secondary phloem and associated secondary xylem (“vascular increments”) embedded in a background of conjunctive tissue (parenchyma, sometimes fibers). Interpretations have varied widely on the ontogeny of this plan. Studies have usually involved one or a few species. The study of numerous taxa, especially in centrospermoid families, leads to the conclusion that there is a common plan, although variations on it are manifold. A master cambium produces secondary cortex externally and, internally, rays, conjunctive tissue, vascular cambia, secondary phloem, and secondary xylem. Secondary phloem and secondary xylem are formed from the vascular cambium in each vascular increment. Vascular cambia function indefinitely, so that a master cambium and a series of vascular cambia (each in a vascular increment) function indefinitely. The master cambium either remains active as long as an axis is actively growing ...
110 citations