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: Anatomical data, when analysed cladistically, support the hypothesis that Spiranthoideae, as currently delimited, are polyphyletic.
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TL;DR: Data on wood anatomy are presented in tabular form for 56 sympetalous families of dicotyledons arranged according to the system of Dahlgren, who was influenced by data from presence or absence of iridoids and by embryological information.
Abstract: Data on wood anatomy are presented in tabular form for 56 sympetalous families of dicotyledons arranged according to the system of Dahlgren, who was influenced by data from presence or absence of iridoids and by embryological information. Each order is reviewed in terms of the degree of correlation of wood data with data from chemistry and embryology. Original data are presented for Buddlejaceae, Globulariaceae, and Selaginaceae. Ericales prove to be a natural and rather primitive group. Cornales as a whole are primitive, but Adoxaceae and Stylidiaceae have distinctively specialized woods (...)
59 citations
TL;DR: It is concluded that the Ericaceae are a paraphyletic assemblage as presently circumscribed, and that Emetraceae andEpacridaceae are better treated as members of theEricaceae.
Abstract: A cladistic analysis of theEricales based on morphological, anatomical, embryological, and phytochemical data has been undertaken. Resulting from the analysis, 56 equally parsimonious cladograms were obtained. The tribeEnkiantheae was found to be the sister-group of the rest of theEricaceae, in which theEmpetraceae, theEpacridaceae, Pyrolaceae, andMonotropaceae are forming derived ingroups. It is thus concluded that theEricaceae are a paraphyletic assemblage as presently circumscribed, and thatEmpetraceae andEpacridaceae are better treated as members of theEricaceae.
59 citations
TL;DR: The results indicate that the substantial activity of PEP carboxylase, incorporation of CO(2) into malate, the high malate content, and in part the relatively low CO( 2) compensation point in Moricandia arvensis may be accounted for by metabolism of nitrate rather than by a state of C(3)-C(4) intermediacy.
Abstract: The leaf anatomy and certain photosynthetic properties of nitrate- and ammonia-grown plants of Moricandia arvensis (L.) DC., a species previously reported to be a C 3 -C 4 intermediate, were investigated. Nitrate-grown plants had a high level of malate in the leaves while ammonia-grown plants had low levels of malate. In young leaves of nitrate-grown plants, there was a diurnal fluctuation of malate content, increasing during the day and decreasing during the night. Titratable acidity remained low in leaves of both nitrate- and ammonia-grown plants. In nitrate-grown plants, the activity of phosphoenolpyruvate (PEP) carboxylase was about 2-fold higher than in ammonia-grown plants, the latter having activity typical of C 3 species. Also, in nitrate-grown plants, the ratio of activities of ribulose 1,5-bisphosphate (RuBP) carboxylase/PEP carboxylase was lower than in ammonia-grown plants. Nitrate reductase activities were higher in nitrate- than in ammonia-grown plants and the greatest activity was found in younger leaves. With nitrate-grown plants, during a pulse-chase experiment the label in malate, as a percentage of the total labeled products, increased from about 7% after a 10-second pulse with 14 CO 2 up to 17% during a 5-minute chase with 12 CO 2 . The pattern of 14 C labeling in various metabolites suggests the primary carboxylation is through RuBP carboxylase with a secondary carboxylation through PEP carboxylase. In similar experiments, with ammonia-grown plants, the percentage label in malate was only 0% to 4% with no increase in malate labeling during the chase period. The CO 2 compensation point was lower in nitrate-grown than ammonia-grown plants. There was no evidence of Kranz-like anatomy in either the nitrate or ammonia-grown plants. Mitochondria of bundle-sheath cells were strikingly positioned along the inner tangential wall. This might allow the chloroplasts of these cells to fix the mitochondrial photorespired CO 2 more effectively and contribute to the low CO 2 compensation point in the species. Chloroplasts of bundle-sheath cells and contiguous mesophyll cells were similar in size and structure in plants grown on different media, although chloroplast thylakoids and stromata of the ammonia-grown plants stained more intensely than those of nitrate-grown plants. In addition, irregular clusters of phytoferritin particles occurred in the chloroplasts of the ammonia-grown plants. The results indicate that the substantial activity of PEP carboxylase, incorporation of CO 2 into malate, the high malate content, and in part the relatively low CO 2 compensation point in Moricandia arvensis may be accounted for by metabolism of nitrate rather than by a state of C 3 -C 4 intermediacy.
59 citations
TL;DR: The occurrence of the fruit wing of Dipterocarpus, together with palynological evidence, indicates unequivocally that a tropical climate and tropical rain forest occurred in Zhangpu during the middle Miocene, warmer and more humid than at the present day.
58 citations