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Topics related to "Gymnosperm"

Gymnosperms
Gymnosperms Gymnosperms are a group of plants that share one common characteristic: they bear seeds, but their seeds do not develop within an ovary. For this reason, gymnosperms were long thought to be an evolutionary precursor to the angiosperms, which are seed plants that enclose their seeds in a... Read more
conifer
conifer [Lat.,=cone-bearing], tree or shrub of the order Coniferales, e.g., the pine , monkey-puzzle tree , cypress , and sequoia . Most conifers bear cones and most are evergreens, though a few, such as the larch , are deciduous. Conifers are widely distributed over the world but are mostly... Read more
cotyledon
cotyledon , in botany, a leaf of the embryo of a seed . The embryos of flowering plants, or angiosperms , usually have either one cotyledon (the monocots) or two (the dicots). Seeds of gymnosperms, such as pines, may have numerous cotyledons. In some seeds the cotyledons are flat and leaflike; in ... Read more
vascular bundle
vascular bundle in botany, a strand of conducting tissue extending lengthwise through the stems and roots of higher plants, including the ferns, fern allies, gymnosperms, and angiosperms. The vascular bundle consists of xylem, which conducts water and dissolved mineral substances from the soil to t... Read more
Pinophyta
Pinophyta , division of the plant kingdom consisting of those organisms commonly called gymnosperms. The gymnosperms, a group that includes the pine, have stems, roots and leaves, and vascular, or conducting, tissue (xylem and phloem). In these plants the ovules, or young seeds, are exposed to the a... Read more
angiosperm
angiosperm , term denoting seed plants in which the ovules, or young seeds, are enclosed within the ovary (that part of the pistil specialized for seed production), in contrast to the gymnosperms, in which the seeds are not enclosed within an ovary. The angiosperms constitute the division Magnoliop... Read more
Robert Brown
Robert Brown 1773-1858, Scottish botanist and botanical explorer. In 1801 he went as a naturalist on one of Matthew Flinders's expeditions to Australia, returning (1805) to England with valuable collections. In his Prodromus florae Novae Hollandiae et Insulae Van Diemen (1810) he described Austra... Read more
cone
cone or strobilus , in botany, reproductive organ of the gymnosperms (the conifers , cycads , and ginkgoes ). Like the flower in the angiosperms (flowering plants), the cone is actually a highly modified branch; unlike the flower, it does not have sepals or petals. Usually separate male (stam... Read more
cycad
cycad , any plant of the order Cycadales, tropical and subtropical palmlike evergreens. The cycads, ginkgoes , and conifers comprise the three major orders of gymnosperms, or cone-bearing plants (see cone and plant ). The cycads first appeared in the Permian period. They are the most primitive... Read more
ginkgo
ginkgo or maidenhair tree, tall, slender, picturesque deciduous tree ( Ginkgo biloba ) with fan-shaped leaves. The ginkgo is native to E China, where it was revered by Buddhist monks and planted near temples. A "living fossil," the ginkgo is the only remaining species of a large order (Gink... Read more

Encyclopedia entries related to "Gymnosperm"

Gymnosperm
Encyclopedia entry from: The Gale Encyclopedia of Science Gymnosperm Gymnosperms are one of the two major groups of...the other is the angio-sperms. Gymnosperm literally means “ naked...an ovary as in the angiosperms. Gymnosperms became common about 290 million years...
gymnosperm
Book article from: World Encyclopedia gymnosperm Seed plant with naked...Most evergreens are gymnosperms. However, larch and...into two main groups: gymnosperms and angiosperms . In the...classification system, gymnosperms comprise three distinct...
Pinophyta
Book article from: The Columbia Encyclopedia, Sixth Edition ...organisms commonly called gymnosperms. The gymnosperms, a group that includes the...pollination, hence the term gymnosperm, meaning naked seed. Pollination...bearing structures of many gymnosperms are organized into a cone...
Angiosperm
Encyclopedia entry from: The Gale Encyclopedia of Science ...the angiosperms over the gymnosperms was the evolution of the...new genetic makeup. The gymnosperms dealt with their immobility...produce as much pollen as gymnosperms, and the resources they...rapidly dominant over their gymnosperm ancestors. Les C. Cwynar
Conifer
Encyclopedia entry from: The Gale Encyclopedia of Science ...seed-producing plants: gymnosperms (meaning “naked...reproductive characteristics: the gymnosperms have egg cells or seeds on...one of the three groups of gymnosperms, which also include the...of four plants having both gymnosperm and angiosperm features...
Pollination
Encyclopedia entry from: The Gale Encyclopedia of Science ...discovered pollen grains of early gymnosperms, which were too large to...certain species of early gymnosperms were pollinated by insects...pollination biology. Most modern gymnosperms and many angiosperms are...x2019; s life cycle. Gymnosperm — Plant which produces...
Cycads
Encyclopedia entry from: The Gale Encyclopedia of Science ...Plantae. The cycads are considered to be gymnosperms, because they bear their seeds naked...cyanobacteria. The cycads are the only gymnosperms known to form symbiotic relationships...plant seen in nature. Cycads and other gymnosperms do not have true flowers and their seeds...
Seed
Encyclopedia entry from: UXL Encyclopedia of Science ...Two kinds of seed plants exist. Gymnosperms are plants that produce naked seeds. The most common type of gymnosperms are conifers, cone-bearing trees...The beginning of growth of a seed. Gymnosperm: A plant that produces naked seeds...
Seed Ferns
Encyclopedia entry from: The Gale Encyclopedia of Science ...so they could be considered primitive gymnosperms. However, the seeds of seed ferns...ferns were very different from modern gymnosperms, such as conifers and cycads, which...to those of cycads, a small group of gymnosperms currently found in tropical and subtropical...
Pines
Encyclopedia entry from: The Gale Encyclopedia of Science ...redwood. Pines and these other conifers are all considered gymnosperms, because they bear their seeds naked, rather than within...sieve areas at the ends. Sieve cells are characteristic of gymnosperms and free-sporing plants, whereas sieve tube elements are...

Dictionary entries related to "Gymnosperm"

gymnosperm
Book article from: A Dictionary of Plant Sciences gymnosperm A seed plant in which the ovules are carried naked on the cone scales, in contrast to the angiosperms , in which they are enclosed by an ovary . Gymnosperms date from the Carboniferous and subsequently they dominated the floras...
Brongniart, Adolphe-Théodore
Dictionary entry from: Complete Dictionary of Scientific Biography ...and the Cretaceous, by ferns and the gymnosperms; the fourth, which was the Tertiary...and three classes of phanerogams: gymnosperms, monocotyledonous angiosperms, and...later publications. For the first time gymnosperms were taken as a class and correctly...
Chamberlain, Charles Joseph
Dictionary entry from: Complete Dictionary of Scientific Biography ...of morphology of the angiosperms and gymnosperms and to methods for the study of plant...New York, 1903); and Morphology of Gymnosperms (Chicago, 1910, 1917). Interested...Plant Science (New York, 1930) and Gymnosperms: Structure and Evolution (Chicago...
antherozoid
Book article from: A Dictionary of Plant Sciences ...of fungi , algae , bryophytes , pteridophytes , and some gymnosperms . The cell is haploid and can move by means of flagella...Antherozoids usually develop in the antheridium (but in some gymnosperms, e.g. Ginkgo , they develop from a cell in the pollen...
ovule
Book article from: A Dictionary of Plant Sciences ovule A structure in angiosperms and gymnosperms that, after fertilization , develops into a seed . In gymnosperms the ovules are unprotected, whereas in angiosperms they are protected by the megasporophyll (which forms the carpel ). One or...
seed plants
Book article from: A Dictionary of Plant Sciences seed plants The group that comprises the gymnosperms and angiosperms , plants distinguished by their production...heterosporous character. These early seed plants were gymnosperms. Angiosperms are not certainly represented in the fossil...
companion cell
Book article from: A Dictionary of Biology ...the adjacent sieve element and to take part in loading and unloading sugar into the sieve element. In gymnosperms a similar function is attributed to albuminous cells , which are found closely associated with gymnosperm sieve elements.
cone
Book article from: A Dictionary of Biology ...1. (in botany) A reproductive structure occurring in gymnosperms, known technically as a strobilus . It consists of sporophylls bearing the spore-producing sporangia. Gymnosperms produce different male and female cones. The large woody...
seed
Book article from: A Dictionary of Biology seed The structure in angiosperms and gymnosperms that develops from the ovule after fertilization. Occasionally...contained within a fruit that develops from the ovary wall. Gymnosperm seeds lack an enclosing fruit and are thus termed naked...
Progymnospermopsida
Book article from: A Dictionary of Earth Sciences ...Progymnospermopsida ( progymnosperms ) The ancestors of the gymnosperms , which arose in the Devonian and dwindled to extinction...Carboniferous . They had trunks with wood resembling that of gymnosperms, but their fertile branches or leaves bore sporangia (see...

Related newspaper, magazine, and trade journal articles from HighBeam Research

Gymnosperm Orthologues of Class B Floral Homeotic Genes and Their Impact on Understanding Flower Origin
Magazine article from: Critical Reviews in Plant Sciences; 1/1/2004; ; 700+ words ; ...extant seed plants. Gymnosperms do not develop petals...is the function of gymnosperm B genes? Recent experiments...from diverse extant gymnosperms are exclusively expressed...strongly suggest that gymnosperm and angiosperm B genes...likely that in extant gymnosperms B genes have a ...
Gymnosperms of southeast Alabama.
Magazine article from: Journal of the Alabama Academy of Science; 7/1/2005; ; 700+ words ; ...comprehensive and detailed work on gymnosperms of the state. Although illustrations...diversity and distribution of gymnosperms found in southeast Alabama...the need for a more current gymnosperm flora and published Gymnosperms of Northeast Alabama and...
A new scheme of classification of living Gymnosperms at family level
Magazine article from: Kew Bulletin; 1/1/2004; ; 700+ words ; ...A new scheme of classification of gymnosperms is proposed in this paper, based mainly...nerved leaved evolutionary line in gymnosperms. Twelve families are involved in the...brief review of phylogenetic systems in Gymnosperms The Gymnosperms were defined by Brown...
Methods of biogeographic analysis and their application to the distribution of Mexican gymnosperms/Los metodos de analisis biogeografico y su aplicacion a la distribucion de las gimnospermas en Mexico/Os metodos de analise biogeografico e sua aplicacao na distribuicao das gimnospermas no Mexico.
Magazine article from: Interciencia; 3/1/2006; ; 700+ words ; ...to the geographic distribution of the gymnosperms of Mexico are presented, and the convenience...Particularly, in the case of Mexican gymnosperms, parsimony analysis of endemicity and...knowledge on the biogeography of Mexican gymnosperms. RESUMO A biogeografia e a disciplina...
Gymnosperms of northeast Alabama and adjacent highlands.(conifer plants)
Magazine article from: Journal of the Alabama Academy of Science; 1/1/2002; ; 700+ words ; ...herbarium; filled square ("") = documented at another herbarium; open circle ("") reported in literature. KEY TO GYMNOSPERM FAMILIES 1. Leaves fan-shaped and deciduous; venation dichotomous (forking) Ginkgoaceae 1. Leaves needle-like or...
Functional Characterization of Nine Norway Spruce TPS Genes and Evolution of Gymnosperm Terpene Synthases of the TPS-d Subfamily1[w]
Magazine article from: Plant Physiology; 8/1/2004; ; 700+ words ; ...synthase and longifolene synthase have not been previously described, and this linalool synthase is the first described from a gymnosperm. These functionally diverse TPS account for much of the structural diversity of constitutive and methyl jasmonate-induced...
Plant genome; biodiversity and evolution; v.1, part D: Phanerogams (Gymnosperm) and (Angiosperm-Monocotyledons).(Brief Article)(Book Review)
Magazine article from: SciTech Book News; 12/1/2007; 537 words ; 9781578084203 Plant genome; biodiversity and evolution; v.1, part D: Phanerogams (Gymnosperm) and (Angiosperm-Monocotyledons) Ed. by A.K. Sharma and Archana Sharma. Science Publishers, Inc. 2006 350 pages $95...
Microarray Analyses of Gene Expression during Adventitious Root Development in Pinus contorta1[w]
Magazine article from: Plant Physiology; 7/1/2004; ; 700+ words ; ...known about development in gymnosperms. Few gymnosperm species have been subjected...molecular genetic analysis. Gymnosperms have several disadvantages...that extant seed plants (gymnosperms and angiosperms) share a...
Conifer R2R3-MYB transcription factors: sequence analyses and din wood-forming tissues of white spruce ( Picea glauca ).(Research article)
Magazine article from: BMC Plant Biology; 3/30/2007; ; 700+ words ; ...lignifying process in gymnosperm trees. Lignins play...regulating lignification in gymnosperms, and their potential...structure of the family in gymnosperms. Therefore, a broader...and other tissues of gymnosperms seems essential for...understanding of their roles in gymnosperm lignin ...
An aquaglyceroporin is abundantly expressed early in the development of the suspensor and the embryo proper of loblolly pine
Magazine article from: Plant Physiology; 12/1/2001; ; 700+ words ; ...angiosperm and gymnosperm embryo ontogeny...many features, gymnosperms have notable...angiosperms, gymnosperm embryogenesis...Also common in gymnosperm embryogeny is...not unique to gymnosperms, their embryos...