Angiosperms
vascular plants that have the ovules and seeds enclosed in an ovary, form the embryo and endosperm by double fertilization, called also flowering plant
Anther
the part of a stamen that produces and contains pollen and is usually borne on a filament
Calyx
the usually green outer whorl of a flower consisting of separate or fused sepals
Carpel
the ovule-bearing structures in an angiosperm differentiated into an ovary, style, and stigma, the innermost whorl of a flower
Double Fertilization
fertilization characteristic of angiosperms in which one sperm nucleus fuses with the egg nucleus to form an embryo and another fuses with polar nuclei to form endosperm
Embyro
the young sporophyte of a seed plant usually comprising a rudimentary plant developing within a seed.
Endosperm
a nutritive tissue in seed plants formed within the embryo sac by division of the endosperm nucleus
Fertilization
an act or process of fecundation, insemination, or pollination, the process of union of two gametes
Filament
the anther-bearing stalk of a stamen
Fruit
the usually edible reproductive body of a seed plant, a mature ovary.
Gymnosperms
a group of vascular plants that produce naked seeds not enclosed in an ovary
Heterosporous
the production of microspores and megaspores, as in seed plants.
Homosporous
the production by various plants (such as the club mosses and horsetails) of asexual spores of only one kind
Megagametophyte
the female gametophyte produced by a megaspore
Megasporangia
a sporangium that contains megaspores
Megaspores
a spore in heterosporous plants giving rise to female gametophytes and usually larger than a microspore
Megasporocyte
megaspore mother cell that divides by meiosis to produce a megaspore.
Microgametophyte
pollen, the male gametophyte produced by a microspore
Microsporangia
a sporangium that contains only microspores.
Microspores
haploid spores in heterosporous plants arising from meiotic division of the microsporocytes in microsporangia and give rise to male gametophytes.
Microsporocyte
a microspore mother cell giving rise to microspores after meiosis.
Nucellus
the central and chief part of a plant ovule that encloses the female gametophyte
Ovary
enlarged basal portion of the carpel, the female organ of a flower. The ovary contains ovules which develop into seeds upon fertilization.
Ovulate cone (ovuliferous)
female pine cone
Petals
one of the modified often brightly colored leaves of the corolla of a flower
Pollen cone
male pine cone.
Pollen grain
the male gametophyte of a seed plant, produced by mitotic divisions of the haploid microspores.
Pollen tube
a tube that is formed by a pollen grain and conveys the sperm nuclei to the embryo sac of an angiosperm or the archegonium of a gymnosperm.
Pollination
the transfer of pollen from an anther to the stigma in angiosperms or from the microsporangium to the micropyle in gymnosperms
Primary growth
vertical growth of plants in roots and shoots (the apical meristems) as a result of cell division
Receptacle
the end of the flower stalk upon which the floral organs are borne. Where modified leaves of the flower are attached together.
Scale
modified leaves or perhaps modified branches of the male or female pine cone.
Seedling
a young plant, especially one raised from seed and not from a cutting.
Seed coat
the outer tissues of the ovule that harden, covering and protecting a seed.
Seeds
the fertilized ripened ovule of a flowering plant containing an embryo and capable normally of germination to produce a new plant.
Secondary growth
an increase in the thickness of the shoots and roots of a vascular plant as a result of the formation of new cells in the cambium
Sepal
one of the modified leaves comprising a calyx.
Stamen
a microsporophyll of a seed plant; the pollen-producing male organ of a flower that consists of an anther and a filament
Stigma
apical part of the carpel of a flower which receives the pollen grains.
Strobilus
the cone of a pine
Style
the elongated part of the pistil bearing a stigma at its apex
Zygote
a cell formed by the union of two gametes--eggs and sperm.