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Consequently, the term "gorgonian coral" is commonly handed to multiple species in the order Alcyonacea that produce a mineralized skeletal axis (or axial-like layer) composed of calcite and the proteinaceous material gorgonin only and corresponds to only one of several families within the formally accepted taxon Gorgoniidae (Scleractinia).
Seed plants, which first appeared in the fossil record towards the end of the Paleozoic era, reproduce using desiccation-resistant capsules called seeds. Starting from a plant which disperses by spores, highly complex changes are needed to produce seeds. The sporophyte has two kinds of spore-forming organs or sporangia.
Non-vascular plants are often among the first species to move into new and inhospitable territories, along with prokaryotes and protists, and thus function as pioneer species. [ citation needed ] Mosses and leafy liverworts have structures called phyllids that resemble leaves , but only consist of single sheets of cells with no internal air ...
Octocorallia (also known as Alcyonaria) is a class of Anthozoa comprising over 3,000 species [1] of marine organisms formed of colonial polyps with 8-fold symmetry. It includes the blue coral, soft corals, sea pens, and gorgonians (sea fans and sea whips) within three orders: Alcyonacea, Helioporacea, and Pennatulacea. [2]
Photosynthetic organisms with plastids of different origin (such as brown algae) do not belong to the Archaeplastida. The archaeplastidans fall into two main evolutionary lines. The red algae are pigmented with chlorophyll a and phycobiliproteins , like most cyanobacteria, and accumulate starch outside the chloroplasts.
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.
Research has shown that measurements of the gorgonin and calcite within species of gorgonian corals can be useful in paleoclimatology and paleoceanography.Studies of the growth, composition, and structure of the skeleton of certain species of gorgonians, (e.g., Primnoa resedaeformis, and Plexaurella dichotoma) can be highly correlated with seasonal and climatic variation.
Unlike most plants they do not have chlorophyll and therefore are non-photosynthetic; rather, they are myco-heterotrophs that obtain food through parasitism on subterranean fungi. Because they do not need any sunlight to live, they can live in very dark sites such as the floor of deep forest. The name "Monotropa" is Greek for "one turn" as ...