Search results
Results from the WOW.Com Content Network
Combined with the five-kingdom model, this created a six-kingdom model, where the kingdom Monera is replaced by the kingdoms Bacteria and Archaea. [16] This six-kingdom model is commonly used in recent US high school biology textbooks, but has received criticism for compromising the current scientific consensus. [ 13 ]
At one time, the cryptogams were formally recognised as a group within the plant kingdom. In his system for classification of all known plants and animals, Carl Linnaeus (1707–1778) divided the plant kingdom into 24 classes, [1] one of which was the "Cryptogamia". This included all plants with concealed reproductive organs.
Marchantia, an example of a liverwort (Marchantiophyta) An example of moss (Bryophyta) on the forest floor in Broken Bow, Oklahoma. Bryophytes (/ ˈ b r aɪ. ə ˌ f aɪ t s /) [1] are a group of land plants (embryophytes), sometimes treated as a taxonomic division, that contains three groups of non-vascular land plants: the liverworts, hornworts, and mosses. [2]
Three goals of plant taxonomy are the identification, classification and description of plants. The distinction between these three goals is important and often overlooked. Plant identification is a determination of the identity of an unknown plant by comparison with previously collected specimens or with the aid of books or identification manuals.
In seed plants (gymnosperms and flowering plants), the sporophyte forms most of the visible plant, and the gametophyte is very small. Flowering plants reproduce sexually using flowers, which contain male and female parts: these may be within the same ( hermaphrodite ) flower, on different flowers on the same plant , or on different plants .
The plants have an underground sexual phase that produces gametes, and this alternates in the lifecycle with the spore-producing plant. The prothallium developed from the spore is a subterranean mass of tissue of considerable size, and bears both the male and female organs ( antheridia and archegonia ). [ 6 ]
[1] [2] George Bentham (1800–1884) and Joseph Dalton Hooker (1817–1911) were British botanists who were closely affiliated to the Royal Botanic Gardens, Kew , in England. Their system of botanical taxonomy was based on the principle of natural affinities and is considered as pre-Darwinian as it does not take evolution into account.
What characterizes an actinorhizal plant is the symbiotic relationship it forms with the bacteria Frankia, [9] in which they infect the roots of the plant. This relationship is what is responsible for the nitrogen-fixation qualities of the plants, and what makes them important to nitrogen-poor environments.