Gymnosperms: Gymnosperms are a group of vascular plants whose seeds are not enclosed by a ripened ovary (fruit), in contrast to ANGIOSPERMS whose seeds are surrounded by an ovary wall. The seeds of many gymnosperms (literally, "naked seed") are borne in cones and are not visible. Taxonomists now recognize four distinct divisions of extant gymnospermous plants (CONIFEROPHYTA; CYCADOPHYTA; GINKGOPHYTA; and GNETOPHYTA).Angiosperms: Members of the group of vascular plants which bear flowers. They are differentiated from GYMNOSPERMS by their production of seeds within a closed chamber (OVARY, PLANT). The Angiosperms division is composed of two classes, the monocotyledons (Liliopsida) and dicotyledons (Magnoliopsida). Angiosperms represent approximately 80% of all known living plants.Picea: A plant genus in the family PINACEAE, order Pinales, class Pinopsida, division Coniferophyta. They are evergreen, pyramidal trees with whorled branches and thin, scaly bark. Each of the linear, spirally arranged leaves is jointed near the stem on a separate woody base.Cycas: A plant genus of the family Cycadaceae, order Cycadales, class Cycadopsida, division CYCADOPHYTA of palm-like trees. It is a source of CYCASIN, the beta-D-glucoside of methylazoxymethanol.Coniferophyta: A plant division of GYMNOSPERMS consisting of cone-bearing trees and shrubs.Pinus: A plant genus in the family PINACEAE, order Pinales, class Pinopsida, division Coniferophyta. They are evergreen trees mainly in temperate climates.Taxus: Genus of coniferous yew trees or shrubs, several species of which have medicinal uses. Notable is the Pacific yew, Taxus brevifolia, which is used to make the anti-neoplastic drug taxol (PACLITAXEL).Pinaceae: A plant family of the order Pinales, class Pinopsida, division Coniferophyta, known for the various conifers.Ginkgo biloba: The only specie of the genus Ginkgo, family Ginkgoacea. It is the source of extracts of medicinal interest, especially Egb 761. Ginkgo may refer to the genus or species.Pinus taeda: A plant species of the genus PINUS which is the subject of genetic study.Cycadophyta: A division of GYMNOSPERMS which look like palm trees (ARECACEAE) but are more closely related to PINUS. They have large cones and large pinnate leaves and are sometimes called cycads, a term which may also refer more narrowly to cycadales or CYCAS.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Zamiaceae: A plant family of the order Cycadales, class Cycadopsida, division CYCADOPHYTA.Ephedra: A plant genus of the family Ephedraceae, order Ephedrales, class Gnetopsida, division Gnetophyta.Ferns: Seedless nonflowering plants of the class Filicinae. They reproduce by spores that appear as dots on the underside of feathery fronds. In earlier classifications the Pteridophyta included the club mosses, horsetails, ferns, and various fossil groups. In more recent classifications, pteridophytes and spermatophytes (seed-bearing plants) are classified in the Subkingdom Tracheobionta (also known as Tracheophyta).Trees: Woody, usually tall, perennial higher plants (Angiosperms, Gymnosperms, and some Pterophyta) having usually a main stem and numerous branches.Selaginellaceae: A plant family of the order Selaginellales, class Lycopodiopsida, division Lycopodiophyta, subkingdom Tracheobionta. Members contain bilobetin. The rarely used common name of resurrection plant is mainly used with CRATEROSTIGMA.Genes, Plant: The functional hereditary units of PLANTS.Ovule: The element in plants that contains the female GAMETOPHYTES.Ocotea: A plant genus in the LAURACEAE family. The common name of stinkwood is also used for Zieria (RUTACEAE).Cambium: A layer of living cells between the bark and hardwood that each year produces additional wood and bark cells, forming concentric growth rings.Pseudotsuga: A plant genus in the family PINACEAE, order Pinales, class Pinopsida, division Coniferophyta. They are coniferous evergreen trees with long, flat, spirally arranged needles that grow directly from the branch.Lignin: The most abundant natural aromatic organic polymer found in all vascular plants. Lignin together with cellulose and hemicellulose are the major cell wall components of the fibers of all wood and grass species. Lignin is composed of coniferyl, p-coumaryl, and sinapyl alcohols in varying ratios in different plant species. (From Merck Index, 11th ed)Cupressaceae: A plant family of the order Pinales, class Pinopsida, division Coniferophyta (conifers). They are mainly resinous, aromatic evergreen trees.DNA, Plant: Deoxyribonucleic acid that makes up the genetic material of plants.Evolution, Molecular: The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.Plants: Multicellular, eukaryotic life forms of kingdom Plantae (sensu lato), comprising the VIRIDIPLANTAE; RHODOPHYTA; and GLAUCOPHYTA; all of which acquired chloroplasts by direct endosymbiosis of CYANOBACTERIA. They are characterized by a mainly photosynthetic mode of nutrition; essentially unlimited growth at localized regions of cell divisions (MERISTEMS); cellulose within cells providing rigidity; the absence of organs of locomotion; absence of nervous and sensory systems; and an alternation of haploid and diploid generations.Gnetum: A plant genus of the family Gnetaceae, order Gnetales class Gnetopsida, division GNETOPHYTA. Members contain STILBENES and benzylisoquinoline alkaloids.Plant Proteins: Proteins found in plants (flowers, herbs, shrubs, trees, etc.). The concept does not include proteins found in vegetables for which VEGETABLE PROTEINS is available.Genome, Chloroplast: The genetic complement of CHLOROPLASTS as represented in their DNA.Genome, Plant: The genetic complement of a plant (PLANTS) as represented in its DNA.Bryophyta: A division of the plant kingdom. Bryophyta contains the subdivision, Musci, which contains the classes: Andreaeopsida, BRYOPSIDA, and SPHAGNOPSIDA.Thysanoptera: An order of very small, fringed-wing INSECTS including many agricultural pests.Cunninghamia: A plant genus of the family TAXODIACEAE. Members contain DITERPENES.Pinus sylvestris: A plant species of the genus PINUS which is the source of pinosylvin. It is sometimes called Scotch pine or Scots pine, which is also a common name for other species of this genus.Phloem: Plant tissue that carries nutrients, especially sucrose, by turgor pressure. Movement is bidirectional, in contrast to XYLEM where it is only upward. Phloem originates and grows outwards from meristematic cells (MERISTEM) in the vascular cambium. P-proteins, a type of LECTINS, are characteristically found in phloem.Seeds: The encapsulated embryos of flowering plants. They are used as is or for animal feed because of the high content of concentrated nutrients like starches, proteins, and fats. Rapeseed, cottonseed, and sunflower seed are also produced for the oils (fats) they yield.Gene Expression Regulation, Plant: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action in plants.DNA Shuffling: The use of DNA recombination (RECOMBINATION, GENETIC) to prepare a large gene library of novel, chimeric genes from a population of randomly fragmented DNA from related gene sequences.Viridiplantae: A monophyletic group of green plants that includes all land plants (EMBRYOPHYTA) and all green algae (CHLOROPHYTA and STREPTOPHYTA).Fossils: Remains, impressions, or traces of animals or plants of past geological times which have been preserved in the earth's crust.Extinction, Biological: The ceasing of existence of a species or taxonomic groups of organisms.Cryptomeria: A plant genus of the family TAXODIACEAE. Its POLLEN is one of the major ALLERGENS.Wood: A product of hard secondary xylem composed of CELLULOSE, hemicellulose, and LIGNANS, that is under the bark of trees and shrubs. It is used in construction and as a source of CHARCOAL and many other products.Seed Dispersal: The various physical methods which include wind, insects, animals, tension, and water, by which a plant scatters its seeds away from the parent plant.Flowers: The reproductive organs of plants.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.DNA, Chloroplast: Deoxyribonucleic acid that makes up the genetic material of CHLOROPLASTS.RNA, Plant: Ribonucleic acid in plants having regulatory and catalytic roles as well as involvement in protein synthesis.Biological Evolution: The process of cumulative change over successive generations through which organisms acquire their distinguishing morphological and physiological characteristics.Expressed Sequence Tags: Partial cDNA (DNA, COMPLEMENTARY) sequences that are unique to the cDNAs from which they were derived.Diterpenes, Kaurane: A group of DITERPENES cyclized into four rings.Plant Leaves: Expanded structures, usually green, of vascular plants, characteristically consisting of a bladelike expansion attached to a stem, and functioning as the principal organ of photosynthesis and transpiration. (American Heritage Dictionary, 2d ed)Pollen: The fertilizing element of plants that contains the male GAMETOPHYTES.