The gymnosperms are a group of seed-producing plants that includes conifers, cycads, Ginkgo, and Gnetales.

The term "gymnosperm" comes from the Greek composite word γυμνόσπερμος (γυμνός gymnos, "naked" and

σπέρμα sperma, "seed"), meaning "naked seeds", after the unenclosed condition of their seeds (called ovules in

their unfertilized state). Their naked condition stands in contrast to the seeds and ovules of flowering plants

(angiosperms), which are enclosed within an ovary. Gymnosperm seeds develop either on the surface of scales

or leaves, often modified to form cones, or at the end of short stalks as in Ginkgo.

The gymnosperms and angiosperms together compose the spermatophytes or seed plants. By far the largest

group of living gymnosperms are the conifers (pines, cypresses, and relatives), followed by cycads, Gnetophytes

(Gnetum, Ephedra andWelwitschia), and Ginkgo (a single living species).

In early classification schemes, the gymnosperms (Gymnospermae) were regarded as a "natural" group. There is

conflicting evidence on the question of whether the living gymnosperms form a clade.[1][2] The fossil record of

gymnosperms includes many distinctive taxa that do not belong to the four modern groups, including seed-

bearing trees that have a somewhat fern-like vegetative morphology (the so-called "seed ferns"

or pteridosperms.)[3] When fossil gymnosperms such as Bennettitales, Caytonia and theglossopterids are

considered, it is clear that angiosperms are nested within a larger gymnosperm clade,

angiosperms

Angiosperms are flowering plants. Angiosperms are the biggest group in the plant kingdom. They have true roots, stems, leaves and flowers. They also have seeds.The seeds are formed when an egg or ovule is fertilized by pollen in the ovary. The ovary is within a flower. The flower contains the male and/or female parts of the plant. Fruits are frequently produced from these ripened ovaries.

Angiosperms are more highly evolved that the algae, mosses, fungi and ferns. Their advanced structures allow angiosperms to thrive on land. They have roots that hold the plant in place and take in needed minerals and water. They have leaves that are the major food makes for the plant. They have stems that hold the plants up and move the nutrients and water about the plant.

Angiosperms the primary food source for animals and provides oxygen for us to breathe. They provide lumber for buildings and other objects, fibers for clothes, are the basis for many drugs, etc..

  Flowers , which are the reproductive structures of an angiosperm and consist of four whorls of modified leaves (from outside in):

Sepals (sepi = fence in) (which collectively are called the calyx), which are often small and green but are colored

like the petals in tulips and lilies, and which generally enclose the flower before it opens

Petals (petal = a leaf, spread out, flat) (which collectively are called the corolla) which are often brightly colored

to attract pollinators (insects, birds, etc.) and may be very simple to highly modified

Stamens (stam(en) = anything standing upright, a thread), the “male” reproductive organs (they make

microspores which turn into male gametophytes), which consist of a stalk (the filament) and a tip (the anther)

where the microspores are produced and turn into pollen (anthe = flower) 

The stamen is the “male” reproductive structure (the microsporophyll), and the anther is the microsporangium.

Microspores are produced and grow into 1n male gametophytes (= pollen) within the anther.

Mature gametophytes are released and transferred to the stigma of the pistil by apollinator (wind, insects, birds,

etc.), and this process is referred to as pollination. Each pollen grain grows a pollen tube into the ovary and its two

sperm nuclei travel down the tube to a female gametophyte.

Pistil (note spelling) or carpel (carpo = a fruit), which consists of:

Ovary (ova, ovi = egg)

the bottom end where seeds are produced

Style (styl, stylo = a pillar, stake, column)

the “stalk” portion

Stigma (stigma = spot)

the outer, sticky tip where pollen sticks when it lands or is placed there