Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Botany”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 505 records · Page 28Linked to original sources
PubMed1987

Adaptation, plant evolution, and the fossil record.

The importance of adaptation in determining patterns of evolution has become an important focus of debate in evolutionary biology. As it pertains to paleobotany, the issue is whether or not adaptive evolution mediated by natural selection is sufficient to explain the stratigraphic distributions of taxa and character states observed in the plant fossil record. One means of addressing this question is the functional evaluation of stratigraphic series of plant organs set in the context of paleoenvironmental change and temporal patterns of floral composition within environments. For certain organ systems, quantitative estimates of biophysical performance can be made on the basis of structures preserved in the fossil record. Performance estimates for plants separated in time or space can be compared directly. Implicit in different hypotheses of the forces that shape the evolutionary record (e.g. adaptation, mass extinction, rapid environmental change, chance) are predictions about stratigraphic and paleoenvironmental trends in the efficacy of functional performance. Existing data suggest that following the evolution of a significant structural innovation, adaptation for improved functional performance can be a major determinant of evolutionary changes in plants; however, there are structural and development limits to functional improvement, and once these are reached, the structure in question may no longer figure strongly in selection until and unless a new innovation evolves. The Silurian-Devonian paleobotanical record is consistent with the hypothesis that the succession of lowland floodplain dominants preserved in the fossil record of this interval was determined principally by the repeated evolution of new taxa that rose to ecological importance because of competitive advantages conferred by improved biophysical performance. This does not seem to be equally true for Carboniferous-Jurassic dominants of swamp and lowland floodplain environments. In these cases, environmental disruption appears to have been a major factor in shaping the fossil record. This does not mean that continuing adaptation was not important during this interval, but it may indicate that adaptive evolution was strongest in environments other than those best represented in the paleobotanical record.

Adaptation, Biological↗
PubMed1984

Tabernaemontana L. (Apocynaceae): a review of its taxonomy, phytochemistry, ethnobotany and pharmacology.

The taxonomy, phytochemistry, ethnobotany, and pharmacology of the genus Tabernaemontana L. (Apocynaceae) is reviewed. The genus is currently being revised taxonomically; most of the segregate genera are being reunited with it and the number of species that will ultimately be recognized will probably be about 100. All the names encountered in the chemical and ethnobotanical literature have been evaluated as far as possible, and a list is presented of the recognized species and their synonyms. The biogenesis and classification of the indole alkaloids found in Tabernaemontana species is set out and some problems in the determination of their stereochemistry are discussed. To facilitate access to the information, three lists have been compiled: the alkaloids in alphabetical order; the alkaloids in order of increasing molecular weight; and the alkaloids grouped according to their biogenetic classification, together with the species and plant part(s) in which they are known to occur. Biogenetic and chemotaxonomic aspects are briefly considered. A table of the non-alkaloidal constituents is also included. The ethnobotany of individual Tabernaemontana species is outlined and an overall assessment made. Likewise, information on the pharmacology of crude extracts and individual alkaloids from Tabernaemontana species has been assembled and appraised.

Alkaloids↗
PubMed1985

Preliminary study of ethnobotany in Xishuang Banna, People's Republic of China.

Xishuang Banna, a particularly rich area for ethnobotanical research, borders on Burma and Laos, and contains some of the last undisturbed tropical rainforests in China. Xishuang Banna is ethnically very diverse; the largest group is the Dai followed by the Hani (Aini) and various smaller national minorities. Since the various groups inhabit different parts of the environment (from river valleys to steep mountain slopes) their awareness of, and use of plants varies considerably. The Dai people for example, have a tradition of forest preserves for each village as well as family home gardens around each house. This study lists 218 plant species that are frequently used by the various nationalities included in the survey.

Botany↗
PubMed1986

The Aloe vera phenomenon: a review of the properties and modern uses of the leaf parenchyma gel.

The mucilaginous gel from the parenchymatous cells in the leaf pulp of Aloe vera has been used since early times for a host of curative purposes. This gel should be distinguished clearly from the bitter yellow exudate originating from the bundle sheath cells, which is used for its purgative effects. Aloe vera gel has come to play a prominent role as a contemporary folk remedy, and numerous optimistic, and in some cases extravagant, claims have been made for its medicinal properties. Modern clinical use of the gel began in the 1930s, with reports of successful treatment of X-ray and radium burns, which led to further experimental studies using laboratory animals in the following decades. The reports of these experiments and the numerous favourable case histories did not give conclusive evidence, since although positive results were usually described, much of the work suffered from poor experimental design and insufficiently large test samples. In addition some conflicting or inconsistent results were obtained. With the recent resurgence of interest in Aloe vera gel, however, new experimental work has indicated the possibility of distinct physiological effects. Chemical analysis has shown the gel to contain various carbohydrate polymers, notably either glucomannans or pectic acid, along with a range of other organic and inorganic components. Although many physiological properties of the gel have been described, there is no certain correlation between these and the identified gel components.

Aloe↗
PubMed1990

A survey of plant crude drugs of Rayalaseema, Andhra Pradesh, India.

An ethnobotanical survey of Rayalaseema of Andhra Pradesh was carried out during 1985-1988. One hundred and thirty-one useful plants currently used by the tribal and non-tribal inhabitants for treating different ailments are presented. Most of the uses of the plants reported by herbalists appear not to have been recorded hitherto. The study reveals some interesting information about the mode of plant use in various ailments either singly or in combination. It has been observed that though the tribes studied live under the same environment and use the same plant species for treating diseases, their prescriptions are quite different. This indicates that these tribes still retain their own traditions so far as treatments are concerned.

Botany↗
PubMed1990

A survey of medicinal plants of minas gerais. Brazil.

A list of fifty-two plant species used for medicinal purposes or to control arthropods by peasants near Belo Horizonte, Minas Gerais (Brazil) has been compiled. Preparation procedures are also noted. The use of plants for controlling insects and to heal a condition known as "ferida brava" is discussed. The role of indigenous plant remedies within the local health care system is worthy of a closer investigation.

Botany↗
PubMed1990

New or uncommon uses of several medicinal plants in some areas of central Italy.

An ethnobotanical investigation was carried out in some areas of Central Italy. Following interviews with various people, several new or unusual therapeutic properties were discovered for many readily available medicinal plants. Sixty-one entities are listed in an alphabetical inventory giving the parts used and method of preparation according to their therapeutic use.

Botany↗
PubMed1990

South American Strychnos species. Ethnobotany (except curare) and alkaloid screening.

The ethnobotanical uses of South American species of Strychnos L. (Loganiaceae) are reviewed, with the exception of their major rôle in the preparation of curare, which will be dealt with in detail elsewhere. Medicinal uses are less common than is the case with the African and Asian species of the genus. About 140 samples, mostly of leaves, belonging to 53 species, have been screened for alkaloids. As with species from other parts of the world, the stem bark and root bark tend to be a richer source than leaves. Nor-harman is present in extracts from S. barnhartiana leaves. Pyridino-indolo-quinolizidinone (angustine-type) bases are also found in several species. The occurrence and pharmacology of the (non-curarizing) alkaloids known to be present in South American Strychnos species is reviewed.

Alkaloids↗
PubMed1991

What is ethnobotany today?

A review is given of contemporary ethnobotany. Emphasis is placed on the interdisciplinary nature of the subject and most progress is made when botanists, anthropologists, ecologists, chemists, etc. work in close collaboration. Ethnoecology, the study of the management systems of indigenous peoples, is particularly important for its application to the creation of sustainable use systems in the tropics. This must include the study of peasant agriculturalists who have adapted many techniques from cultures that have long been extinct. Quantitative studies of the extent to which rainforest Indians use the forest have provided many data useful for conservation. The study of indigenous medicines is leading to the discovery of new medicines and agrochemicals. When commercial benefit is gained from products derived from information obtained from indigenous peoples, it is essential to ensure that they and their countries benefit from the royalties. There is a great urgency for further ethnobotanical research before indigenous cultures and natural habitats are destroyed.

Agriculture↗
PubMed1993

Botanical methods in ethnopharmacology and the need for conservation of medicinal plants.

An imperative demand imposed on all scientific investigations is that they should be repeatable, which calls for adequate documentation from the very beginning. In medicinal plant research, botanical documentation plays a vital role since without correctly identified material and properly documented voucher specimens the results are at best suspect and at worst useless. The botanical contributions required for ethnopharmacological research thus include adequate naming of the material and deposition of properly labelled voucher specimens in at least two public herbaria. Ethnopharmacology depends, however, upon botanical assistance also in another respect, viz. concerning conservation. This field may seem to have little to do with ethnopharmacology, but without joint efforts to save the useful plants from extinction, ethnopharmacology will lose important parts of its main source at an appalling rate.

Botany↗