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The word "slate" is also used for certain types of object made from slate rock. It may mean a single roofing tile made of slate, or a writing slate , which was traditionally a small, smooth piece of the rock, often framed in wood, used with chalk as a notepad or notice board, and especially for recording charges in pubs and inns.
Plant anatomy or phytotomy is the general term for the study of the internal structure of plants.Originally, it included plant morphology, the description of the physical form and external structure of plants, but since the mid-20th century, plant anatomy has been considered a separate field referring only to internal plant structure.
The ground tissue of plants includes all tissues that are neither dermal nor vascular. It can be divided into three types based on the nature of the cell walls. This tissue system is present between the dermal tissue and forms the main bulk of the plant body. Parenchyma cells have thin primary walls and usually remain alive after they become ...
Permineralization is a process of fossilization of bones and tissues in which mineral deposits form internal casts of organisms. Carried by water, these minerals fill the spaces within organic tissue. Because of the nature of the casts, permineralization is particularly useful in studies of the internal structures of organisms, usually of ...
Phytoliths (from Greek, "plant stone") are rigid, microscopic mineral deposits found in some plant tissues, often persisting after the decay of the plant. Although some use "phytolith" to refer to all mineral secretions by plants, it more commonly refers to siliceous plant remains. Phytoliths come in varying shapes and sizes.
In vascular plants, the diploid sporophyte has evolved as the dominant and visible phase of the life cycle. In seed plants and some other groups of vascular plants the gametophyte phases are strongly reduced in size and contained within the pollen and ovules. The female gametophyte is entirely contained within the sporophyte's tissues, while ...
The slate deposits in this region of northern Spain are over 500 million years old, having formed during the Palaeozoic period. The colour and texture of the slate produced is largely dependent upon the tectonic environment, the source of the sedimentary material from which the slate is comprised, and the chemical and physical conditions ...
The detailed study of reproductive structures in plants led to the discovery of the alternation of generations, found in all plants and most algae, by the German botanist Wilhelm Hofmeister. This discovery is one of the most important made in all of plant morphology, since it provides a common basis for understanding the life cycle of all plants.