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: Two most parsimonious cladograms are obtained using a data set of 100 characters derived from morphology, anatomy, embryology, chemistry, and karyology, combined with three nucleotide sequence data sets in a phylogenetic analysis of all 12 currently recognized families in the angiosperm order Asterales.
Abstract: We obtained two most parsimonious cladograms using a data set of 100 characters derived from morphology, anatomy, embryology, chemistry, and karyology, combined with three nucleotide sequence data sets (the chloroplast genes atpB, ndhF, and rbcL) in a phylogenetic analysis of all 12 currently recognized families in the angiosperm order Asterales, represented by 40 genera. Most clades were supported by a jackknife value of at least 50% and a Bremer support of 5 or more. Rousseaceae sensu lato (including Carpodetaceae), together with Pentaphragmataceae and Campanulaceae s.l., is the sister group to the rest of the Asterales. A sister group relationship between Donatia and Stylidiaceae is well supported both morphologically and by molecular data, and we suggest that Donatia should again be treated as a subfamily in Stylidiaceae. The sister group relationship between Calyceraceae and Asteraceae is well supported.
95 citations
Cites background from "Anatomy of the Dicotyledons."
...…palynological, karyological, and chemical data collected from standard literature (Metcalfe and Chalk 1950, 1979, 1983; Hegnauer 1964, 1966, 1969a, 1969b, 1973, 1989, 1990; Davis 1966; Gibbs 1974; Corner 1976; Cutler and Gregory 1998) as well as more specific literature (referred to in app....
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94 citations
TL;DR: It was observed that trichomes can be successfully used for the delimitation of genera within the Compositae (Asteraceae) family, and foliar anatomical characters that justify the separation of Vernonia amygdalina and Vernonia cinerea into separate tribes are highlighted.
Abstract: A comparative study of the leaf epidermis of twelve species in the Compositae (Asteraceae) family was undertaken in order to document characters that are important in the taxonomy of the family. It was observed that trichomes can be successfully used for the delimitation of genera within the family. Within each species however, there are varied assortment of trichomes with occasional transitions among them. Launaea taraxacifolia was unique in being the only species without any trichome. Stellate trichome type and K-shaped or tetraradiate trichomes were observed in Tridax procumbens only. The genus Vernonia can be delimited from the other genera by the possession of T - shaped trichomes which are absent in the other genera, while amoeboid-shaped trichomes can be found in the genus Chromolaena only. Within the same genus, the species can also be delimited on the basis of possession of unique trichome types, for example in the genera Vernonia and Emilia. Cuticular striations occur in only two species out of the twelve studied, on the abaxial surface of V. amygdalina and on both surfaces of Bidens pilosa. Four stomatal types were recorded for the family, anomocytic, brachyparacytic, anisocytic and diacytic. Stomatal type was observed to delimit not only at generic level, but also at specific or species level. Ageratum conyzoides and Synedrella nodiflora are the only two species with occasional diacytic stomatal types. Results of the statistical correlation analysis for stomatal size and stomatal index at the 0.05 and 0.01 levels revealed high positive correlation for species in the same tribe, as well as for species in different tribes affirming close interrelationship and overlap of the values of stomatal indices and sizes within the family. Foliar anatomical characters that justify the separation of Vernonia amygdalina and Vernonia cinerea into separate tribes are highlighted.
93 citations
TL;DR: A trend is evident from mostly mesophyll prismatics in Padus to fewer prismatics and more druses of mixed distribution in Laurocerasus and Cerasus, to mostly druses restricted to veins in Amygdalus and Prunophora.
Abstract: Calcium oxalate crystal types and distribution within leaves ofPrunus sensu lato (Rosaceae; Prunoideae) were surveyed from mostly herbarium specimens (196 specimens of 131 species of all five subgenera usually recognized). Rehydrated samples were bleached, mounted unstained, and viewed microscopically between crossed polarizers. Six patterns were recognized based on crystal type and relative distribution around veins and in mesophyll. Druses predominate in four subgenera, but prismatics are most common in subgenus Padus. Prunophora and Amygdalus, considered to be the most advanced subgenera, have virtually only druses, which are almost always associated with veins. Cerasus and Laurocerasus, intermediate subgenera, have the greatest diversity of patterns, but few species with prismatics. A trend is evident from mostly mesophyll prismatics in Padus to fewer prismatics and more druses of mixed distribution in Laurocerasus and Cerasus, to mostly druses restricted to veins in Amygdalus and Prunophora.
93 citations
TL;DR: It was found that treatment at 200 and 210 degrees C led to samples that were difficult to delignigy because the destructuring and disintegration of lignocellulosic materials were insufficient, and a temperature of the order of 220-230 degrees C is required to obtain well-separated fibres.
93 citations