The Diversity of The World of Life

Green Plants (Viridaeplantae)

Flowering Plants,

Including "Hardwoods"

(Anthophyta, Magnoliophyta, or Angiospermae)

Biology

Representatives

Note:  The plants in the following list are organized by families (groups ending in "-aceae"), orders (groups ending in "-ales"), and higher groups (as generally recognized by botanists); they are not arranged alphabetically.  To find a specific plant in this lengthy list (Flowering plants are the most successful and diverse group of plants), you may use your browser's "Edit > Find (on This Page)" function (And search for more than one instance on the page:  Two or more plants may have the same common name even though they are in different families).

Primitive Flowering Plants

     (Nymphaeales)

          Water-Lily etc. (Nymphaeaceae)

     (Austrobaileyales)

          Star Anise etc. (Illiciaceae)

     (Piperales)

          Birthworts, Dutchman's Pipe, Wild Ginger, etc.

          (Aristolochiaceae)

          Pepper, Peperomia, etc. (Piperaceae)

          Lizard's-Tail, Yerba Mansa, etc. (Saururaceae)

     (Winterales)

          Winter's Bark etc. (Winteraceae)

     (Laurales)

          Calycanthus etc. (Calycanthaceae)

          Laurel, Cinnamon, Camphor, Avocado, Sassafras, etc.

          (Lauraceae)

     (Magnoliales)

          Custard-Apple, Pawpaw, etc. (Annonaceae)

          Magnolia, Tulip Trees, etc. (Magnoliaceae)

          Nutmeg etc. (Myristicaceae)

     (Ceratophyllales)

          Aquatic Hornworts (Ceratophyllaceae)

Monocots (Flowering plants with just one "cotyledon" (seed leaf), instead of the usual two)

     (Alismatales)

          Water-Plaintain etc. (Alismataceae)

          Arum, Anthurium, Caladium, Calla Lily, Dieffenbachia,

          Jack-in-the-Pulpit, Philodendron, Skunk Cabbage, etc.

          (Araceae)

          Frog's-Bit, Elodea, etc. (Hydrocharitaceae)

          Arrow-Grass etc. (Juncaginaceae)

          Pondweed etc. (Potamogetonaceae)

          Eelgrass etc. (Zosteraceae)

     (Asparagales)

          Lily of the Nile etc. (Agapanthaceae)

          Agave, Sisal, Aloe, Century Plant, Yucca, etc. (Agavaceae)

          Garlic, Onion, Leek, Chive, etc. (Alliaceae)

          Snowdrop, Narcissus, Daffodil, Amaryllis, etc. (Amaryllidaceae)

          Asparagus etc. (Asparagaceae)

          Day Lily, Hemerocallis, etc. (Hemerocallidaceae)

          Hyacinth etc. (Hyacinthaceae)

          Iris, Crocus (including Saffron), Freesia, Gladiolus, etc.

          (Iridaceae)

          Orchids, including Vanilla (Orchidaceae)

          Grass Tree etc. (Xanthorrhoeaceae)

     (Dioscoreales)

          Yams etc. (Dioscoreaceae)

     (Liliales)

          Colchicum, Gloriosa, Naked Lady, etc. (Colchicaceae)

          Lilies etc. (Liliaceae)

     (Pandanales)

          Screw-Pine etc. (Pandanaceae)

Commelinoids

     (Abolbodales)

          Bromeliads:  Pineapple etc. (Bromeliaceae)

     (Arecales)

          Palms (Arecaceae)

     (Commelinales)

          Spiderworts (Commelinaceae)

          Bloodwort etc. (Haemodoraceae)

          Pickerelweed, Water Hyacinth, etc. (Pontederiaceae)

     (Poales)

          Bulrush, Papyrus, Umbrella Plant, Sedge, etc. (Cyperaceae)

          Pipewort etc. (Eriocaulaceae)

          Rushes (Juncaceae)

          Grasses, including Grains:  Cereals (Rice, Wheat, Corn, Oats,

          Barley, Rye, etc.), Sugar Cane, Bamboo, Reeds, etc.

          (Poaceae)  Note:  Although their "amino acids" must be

          supplemented in our diets with the amino acids from legumes (in

          order for the metabolism of our body to synthesize proteins),

          grains have always been "the staff of life" for human civilizations.

          Bur-Reed (Sparganiaceae)

          Cattails (Typhaceae)

          Yellow-Eyed Grass (Xyridaceae)

     (Zingiberales)

          Canna (Cannaceae)

          Heliconia (Heliconiaceae)

          Arrowroot etc. (Marantaceae)

          Ginger, Cardamom, etc. (Zingiberaceae)

Eudicots (Dicots have two "cotyledons" (seed leaves))

     (Buxales)

          Box etc. (Buxaceae)

     (Proteales)

          Lotus (Nelumbonaceae)

          Plane Trees, Sycamore, etc. (Platanaceae)

          Protea, Macadamia, etc. (Proteaceae)

     (Ranunculales)

          Barberry etc. (Berberidaceae)

          Moonseed etc. (Menispermaceae)

          Poppies (Papaveraceae)

          Buttercup, Anemones, Clematis, Crowfoot, Delphiniums,

          Ranuculus, etc. (Ranunculaceae)

Core Eudicots

     (Aextoxicales)

          Grapes etc. (Vitaceae)

     (Caryophyllales)

          Carpetweeds, Fig Marigolds, New Zealand Spinach, etc.

          (Aizoaceae)

          Amaranth etc. (Amaranthaceae)

          Cactus (Cactaceae)

          Carnation, Dianthus, Pink, Chickweed, etc. (Caryophyllaceae)

          Goosefoot, Beet, Sugarbeet, Chard, Spinach, Pigweed, etc.

          (Chenopodiaceae)

          (Carnivorous) Sundew (Droseraceae)

          Four-O'Clocks etc. (Nyctaginaceae)

          Pokeweed etc. (Phytolaccaceae)

          Leadwort, Sea-Lavender, etc. (Plumbaginaceae)

          Buckwheat, Docks, Rhubarb, etc. (Polygonaceae)

          Purslane, Portulaca, etc. (Portulacaceae)

          Tamarisk etc. (Tamaricaceae)

     (Santales)

          Mistletoe etc. (Loranthaceae)

          Sandalwood etc. (Santalaceae)

     (Saxifragales)

          Stonecrop, Crassula, etc. (Crassulaceae)

          Gooseberry, Currants, etc. (Grossulariaceae)

          Water-Milfoil etc. (Haloragaceae)

          Witch-Hazel, Liquidambar, Corylopsis, etc. (Hamamelidaceae)

          Peonies (Paeoniaceae)

          Saxifrage etc. (Saxifragaceae)

Rosids

     (Aphloiales)

          Bean-Caper, Lignum Vitae, etc. (Zygophyllaceae)

     (Geraniales)

          Geraniums (Geraniaceae)

Eurosids I

     (Celastrales)

          Bittersweet, Spindle Tree, Staff Tree, etc. (Celastraceae)

     (Cucurbitales)

          Begonias (Begoniaceae)

          Cucurbits:  Cucumber, Melons, Squash, Pumpkin, Gourds, etc.

          (Cucurbitaceae)

     (Fabales)

          Legumes:  Beans, Garbanzos, Peas, Cowpeas, Chickpeas,

          Peanut, Soybean, Lentil, Clover, Alfalfa, Vetch, Locoweed,

          Kudzu, Laburnum, Acacia, Mimosa, Wisteria, etc. (Fabaceae)

          Note:  The "amino acids" in legumes must be supplemented in our

          diets with the amino acids from grains, in order for the metabolism

          of our body to synthesize proteins.

          Milkwort, Seneca, Snakeroot, etc. (Polygalaceae)

     (Fagales)

          Birch, Alders, Hazel, etc. (Betulaceae)

          Beeches, Chestnuts, Oaks, etc. (Fagaceae)

          Butternuts, Walnuts, Hickories, Pecans, etc. (Juglandaceae)

          Wax-Myrtle etc. (Myricaceae)

     (Malpighiales)

          St. John's Wort, Mangosteen, etc. (Clusiaceae)

          Spurge, Cassava, Castor Oil Plant, Croton Oil Plant, etc.

          (Euphorbiaceae)

          Flax etc. (Linaceae)

          Passionflowers (Passifloraceae)

          Mangroves (Rhizophoraceae)

          Willows & Poplars (Salicaceae)

          Violets, Pansies, etc. (Violaceae)

     (Oxalidales)

          Australian Pitcher Plant (Cephalotus)

          Zebrawood etc. (Connaraceae)

          Elaeocarpus (Elaeocarpaceae)

          Wood Sorrel (Oxalis), Carambolas, etc. (Oxalidaceae)

     (Rosales)

          Hemp, Marijuana, Hops, etc. (Cannabaceae)

          Oleaster etc. (Elaeagnaceae)

          Mulberry, Figs (including Certain Rubber Trees), Breadfruit,

          etc. (Moraceae)

          Buckthorn, Jujubes, etc. (Rhamnaceae)

          Rose, Strawberry, Brambles (Raspberry, Blackberry,

          Boysenberry, Loganberry, etc.), Pome Fruits (Apple,

          Crabapple, Pear, & Quince), Stone Fruits (Peach, Nectarine,

          Apricot, Cherry, Plum, Prune, Almond, etc.), Chokecherry,

          Spirea (Spiraea), Hawthorns, Cotoneaster, Pyracantha,

          Mountain Ash, Serviceberry, etc. (Rosaceae)

          Elms etc. (Ulmaceae)

          Nettles etc. (Urticaceae)

Eurosids II

     (Brassicales)

          Crucifers:  Cabbage, Brussels Sprouts, Broccoli, Cauliflower,

          Collards, Kale, Mustard, Cress, Kohlrabi, Turnip, Rutabaga,

          Radish, Horseradish, Lunaria, Alyssum, Lunaria, Candytuft,

          Shepherd's Purse, etc. (Brassicaceae)

          Papaya etc. (Caricaceae)

          Mignonette etc. (Resedaceae)

          Salvadora etc. (Salvadoraceae)

          Nasturtium etc. (Tropaeolacae)

     (Malvales)

          Rockrose etc. (Cistaceae)

          Mallows, Cotton, Flowering Maple, Hibiscus, Hollyhocks,

          Okra, etc. (Malvaceae)

          Daphne, Leatherwood, etc. (Thymelaeaceae)

     (Myrtales)

          Loosestrife, Crepe Myrtle, etc. (Lythraceae)

          Myrtles, Allspice, Guavas, etc. (Myrtaceae)

          Evening Primrose, Fuchsia, etc. (Onagraceae)

     (Sapindales)

          Cashew, Mango, Pistachio, Poison Ivy, Sumac, etc.

          (Anacardiaceae)

          Incense Tree etc. (Burseraceae)

          Mahogany etc. (Meliaceae)

          Rue, Citrus (Orange, Lemon, Lime, Grapefruit, Pomelo,

          Tangerine, etc.), Kumquats, etc. (Rutaceae)

          Soapberry, Litchi, etc. (Sapindaceae)

          Quassia, Bitterwood Tree, etc. (Simaroubaceae)

Asterids

     (Cornales)

          Dogwood etc. (Cornaceae)

          Hydrangea etc. (Hydrangeaceae)

     (Ericales)

          Kiwi etc. (Actinidiaceae)

          Balsam, Impatiens, etc. (Balsaminaceae)

          White Alder etc. (Clethraceae)

          Ebony, Persimmons, etc. (Ebenaceae)

          Heath, Heathers, Cranberry, Blueberry, Arbutus,

          Andromedas, Manzanita, Rhododendron, etc. (Ericaceae)

          Anchovy Pear, Brazil Nut, etc. (Lecythidaceae)

          Phlox etc. (Polemoniaceae)

          Primrose, Cyclamen, Loosestrife, etc. (Primulaceae)

          Sapodilla (including Chicle Gum Tree), Sapote, Gutta-Percha

          Trees, Buckthorn, etc. (Sapotaceae)

          (Carnivorous) Pitcher Plants (Sarraceniaceae)

          Styrax, Storax, etc. (Styracaceae)

          Sweetleaf etc. (Symplocaceae)

          Tea, Camellia, etc. (Theaceae)

Euasterids I

     (Boraginales)

          Borage, Comfrey, Forget-Me-Nots, etc. (Boraginaceae)

     (Gentianales)

          Dogbane, Oleander, Periwinkles, etc. (Apocynaceae)

          Gentians etc. (Gentianaceae)

          Jasmine, Butterfly Bush, etc. (Loganiaceae)

          Madders, Coffee, Gardenias, etc. (Rubiaceae)

     (Lamiales)

          Acanthus, Black-Eyed Susan, etc. (Acanathaceae)

          Black & White Mangroves (Avicenniaceae)

          Bignonia, Trumpet Vine, Catalpa, Calabash, etc.

          (Bignoniaceae)

          Gesnerias, Gloxinias, etc. (Gesneriaceae)

          Mints, Thyme, Sage, Rosemary, Horehound, Basil, Coleus,

          Hyssops, Lavender, etc. (Lamiaceae)

          (Carnivorous) Bladderworts, Butterworts, etc.

          (Lentibulariaceae)

          Olive, Ash, Jasmine, Privet, Lilacs, Forsythia, etc. (Oleaceae)

          Broomrape etc. (Orobanchaceae)

          Sesame etc. (Pedaliaceae)

          Plantains (Plantaginaceae)

          Figwort, Foxglove, Snapdragon, Toadflax, Mullein, etc.

          (Scrophulariaceae)

          Verbena, Lantana, Teak, etc. (Verbenaceae)

     (Solanales)

          Morning Glory, Bindweed, Sweetpotato, Dodder, etc.

          (Convolvulaceae)

          Potato, Tomato, Chili & Bell Peppers, Eggplant, Ground

          Cherry, Bittersweet, Belladonna, Nightshade, Tobacco, etc.

          (Solanaceae)

Euasterids II

     (Apiales)

          Umbels:  Carrot, Celery, Parsnips, Parsley, Anise, Caraway,

          Cumin, Dill, Chervil, Hemlock, etc. (Apiaceae)

          Ivy, Ginseng, Umbrella Tree, etc. (Araliaceae)

     (Aquifoliales)

          Holly etc. (Aquifoliaceae)

     (Asterales)

          Composites:  Asters, Burdock, Chrysanthemums, Daisy,

          Dandelion, Everlastings, Goldenrod, Lettuce, Marigold,

          Ragweeds, Sagebrush, Sunflower, Tarragon, Thistles,

          Wormwood, Yarrow, Zinnia, etc. (Asteraceae)

          Bellflower, Lobelias, etc. (Campanulaceae)

          Buckbean, Bogbeans, etc. (Menyanthaceae)

     (Dipsacales)

          Honeysuckle, Abelia, Woodbine, Snowberry, Waxberry, Elder,

          Elderberry, Cranberry Bush or Tree, Arrow Wood, Viburnum,

          Weigela, etc. (Caprifoliaceae)

          Teasel, Scabiosa, etc. (Dipsacaceae)

          Valerians etc. (Valerianaceae)

Biology

ENVIRONMENTS

Most flowering plants live on land, some live on or in water, and a relative few live on other plants.  Flowering plants are the most widely distributed plants in the world; in particular, grasses are dominant in more terrestrial habitats than are any other group of plants in the "Cenozoic" (modern geologic era).

OVERALL STRUCTURE

Cell walls, composed primarily of cellulose (and related "polysaccharides"), give shape to individual cells.

Forming either a fibrous or "taproot" system, the roots of a flowering plant anchor it to the soil, absorb water (with dissolved minerals etc.) from the soil, and conduct water (with dissolved substances) up to shoots and photosynthesized foods down from shoots.  Although they do not have typical buds, as on shoots, some roots do form shoots and side roots from "adventitious" buds.

On shoots, new growth arises from buds, which form at shoot tips and in "axils" (where leaves or side-branches meet the stem).  A sequence of short days followed by low temperatures may induce the scale-protected buds of woody plants to go and stay dormant, as in fall and over winter.

Young, "primary" growth of roots or shoots is growth in length, via cell division (in the "apical meristems" of root- and shoot-tips) coupled with cell elongation (in an "elongation zone", typically just behind the apical meristem).  In contrast, woody, "secondary" growth of roots or shoots is growth in girth, via cell division (in the "vascular cambium", between the bark and wood of older roots and stems).  In such "monocot" trees as palms, primary growth continues at the top of the shoot; but there is no true secondary, woody growth.

Produced from shoot tips in definite, species-specific patterns, the leaves of flowering (typically "broad-leaved") plants are typically flat and thin, with "petioles" (leafstalks) and "veins" (which strengthen the blades and, being composed of vascular tissue, conduct water with dissolved substances, from the roots, as well as foods, photosynthesized within the leaves).

"Dicots" (typical flowering plants) are very small to very large plants with fleshy to woody roots, fleshy to woody stems (one trunk in trees, more in shrubs), typically broad leaves (either evergreen or deciduous) with net-patterned veins, and flowers whose parts are typically arranged in groups of four or five.

"Monocots" (such as grasses or palms) are small to large plants with typically fleshy roots, typically fleshy stems, typically strap-like leaves with parallel-patterned veins, and flowers (beardlike in grasses) whose parts are typically arranged in groups of three.

ENERGY CAPTURE

Although a few flowering plants are parasitic on other plants (such as mistletoe on various trees) and others (such as the Venus flytrap) are "saprophytic" (living on decaying organic matter, such as flies they trap and kill), in most flowering plants light-energy is captured, for photosynthesis, by chloroplasts, especially within the (thin-walled, undifferentiated) "parenchyma" cells between the upper and lower "epidermis" of leaves.  Some grasses perform an extraordinarily efficient type of photosynthesis (Sugar cane is perhaps the fastest growing organism on land, although it is still out-performed by giant kelp, in the sea -- seawater and "floats" provide buoyancy to the kelp, which, thus, does not need to invest as much materials and energy in supportive structures).

EXCHANGE OF MATERIALS WITH THE ENVIRONMENT

Water vapor and gases flow especially through "stomata" pores (each regulated by a pair of "guard cells") in leaves -- carbon dioxide flows in and oxygen flows out for photosynthesis, during the day; and oxygen flows in and carbon dioxide flows out for respiration, both day and night (Typically, there is net influx of oxygen and outflux of carbon dioxide at night; the reverse is true during the daylight hours; and over the entire, 24-hour course of a day, green plants, unlike animals, typically consume more carbon dioxide than they produce and produce more oxygen than they consume).

"Transpiration" is the evaporation of water from plant tissues, especially thin leaves.  A waxy "cuticle" over the epidermal cells of flowering plants helps prevent water loss from shoots, bark helps prevent water loss from any woody stems of dicots, and hardened outer tissues help prevent water loss from the shoots of monocots.

Gases are also exchanged through "lenticel" openings in bark.

Bark and other protective outer structures can act as barriers to pathogens, parasites, and predators (which can also be repelled by such external growths as spines or thorns).

Countless "root hairs", growing out into the soil from the tips of roots just behind the cell-elongation zone, absorb most of the water and dissolved minerals for vascular plants.  The soil -- consisting of both inorganic and organic matter, both living and non-living -- provides roots with support, air, water, and minerals.  The chemical elements required for plant life are easily remembered by reciting this little saying:  "C. Hopkin's Cafe, managed by my cousins Mo and Clyde" -- carbon dioxide and water provide C [carbon], H [hydrogen], and O [oxygen]; soil minerals provide P [phosphorus], K [potassium], N [nitrogen], S [sulfur], Ca [calcium], Fe [iron], Mg [magnesium], B [boron], Mn [manganese], Cu [copper], Zn [zinc], Mo [molybdenum], and Cl [chlorine] (Additional elements are sometimes required, particularly by certain plants in certain soils).

INTERNAL TRANSPORT

The stems and roots of flowering plants, like other "vascular" plants, are composed of various layers and tissues, the arrangement in young, typically fleshy "primary" stems and roots typically maturing into a different pattern in older, woody "secondary" stems and roots.

Typically, the outermost tissue in the young, primary stem of a flowering plant is the "epidermis", composed of water-conserving "epidermal cells" (flat and wax-coated), "guard cells" (two around each "stomata" air-hole), and/or "epidermal hairs" (trapping humidity).  Under the epidermis is the "cortex", composed of "collenchyma" cells (flexible but supportive), "sclerenchyma" fibers (woody) and "sclerids" (stony), and food- and water-storing "parenchyma" cells (thin-walled and undifferentiated).  Within the cortex of the primary stem lies the vascular tissue, composed of food-conducting "phloem" tissue (consisting of supportive fibers, conductive living "sieve-tube members" accompanied by "companion cells", and food-storing parenchyma cells) and water-conducting "xylem" tissue (consisting of supportive fibers, supportive and conductive non-living "tracheids" and "vessel elements", and food-storing parenchyma cells).  Forming the core of the primary stem is the "pith", composed mostly of food- and water-storing parenchyma cells reinforced with sclerids.

Typically, the vascular tissues in a primary stem are grouped together in "vascular bundles", typically with the phloem lying to the outside and the xylem lying to the inside, a thin layer of "meristematic" cells (active in cell division) sandwiched in between.  The vascular bundles, forming strands running the length of the stem, are arranged in a circle (in a cross-section of the stem) and are separated by "pith rays", extending out from the central pith.  In monocots, the vascular bundles are distributed throughout the cross-section of the stem, not just arranged in a circular pattern.

When present, secondary growth in the stem of a dicot is laid down by a cylinder of "vascular cambium", which is formed from the meristematic tissue remaining between the primary phloem and xylem (within each vascular bundle) plus some of the parenchyma cells in the pith rays (between the vascular bundles):  The vascular cambium is circular in cross-section.  Laid-down to the outside is "secondary phloem", which (with corky tissues produced from "cork cambiums", arising outside of the phloem) form the bark; and laid-down to the inside (in annual rings, in Temperate climates) is "secondary xylem", consisting of young, active "sapwood", which eventually matures into inactive "heartwood" (which eventually crushes the central pith of the primary stem).

Secondary tissues are typically not produced in monocots, although there is a fibrous -- un-grained -- "wood" in such monocots as palm trees.

Typically, the young, primary tissues in the root of a flowering plant are (from the outside in) the protective epidermis, the food-storing cortex (with the filtering "endodermis" as its innermost layer of cells), the "pericycle" (which may eventually produce side roots and secondary tissues), and (forming the core of the primary root) the vascular tissues -- the water-conducting primary xylem (star-shaped in cross-section) and the food-conducting primary phloem (lying in between the arms of the xylem).   Unlike in stems, there is no pith in the center of the roots of dicots and many monocots.

When present, secondary growth in the root of a flowering plant is laid-down by a vascular cambium formed from "procambium" cells (meristematic cells remaining between the primary xylem and phloem) plus certain cells of the pericycle (namely, those around the tips of xylem arms):  Like in the stem, to the outside is laid-down secondary phloem, which (with tissues from cork cambiums, arising to the exterior) forms the bark; and to the inside is laid-down secondary xylem (wood).

The phloem of flowering plants typically includes living sieve-tube members, which are connected end-to-end via "sieve plates" into "sieve tubes" and are typically regulated -- and probably powered -- by smaller "companion cells".

The xylem of flowering plants typically includes not only non-living tracheids (communicating via "pit pairs" in their side walls) but also non-living "vessel elements" (strengthened by ringlike, spiral, or pitted thickenings in their side walls and connected via perforations in their end walls into water-conducting "vessels").

Typically, a watery solution or mixture of sugars and other food molecules, photosynthesized in leaves, is "translocated" through phloem tissue, down to roots and out to other food-consuming "sinks":  Theoretically, food molecules are actively transported into and out of the living phloem cells; and water follows by "osmosis", creating positive water pressure within the phloem and within growing, food-consuming cells.

In contrast, water with dissolved minerals and other substances, absorbed in roots, moves through non-living xylem tissue, up to leaves:  Theoretically, water molecules are "transpired" (evaporated by solar energy) through the stomata (pores in leaves); and a column of water (held together by its "hydrogen bonds") follows by "cohesion", under negative pressure (tension) within the non-living xylem.

In healthy plants, a copious production of rubbery "latex" or other sap can kill invading pests.

DEVELOPMENTAL CONTROL

The growth and development of flowering plants is under genetic control, as typically determines leaf-shape and flower-structure -- both features are typically useful in identifying plants (although leaf-shape sometimes varies with the age of the plant or with environmental conditions).

The growth and development of flowering plants is also under hormonal control.  Hormones -- in various concentrations and combinations, in various tissues, at various times -- regulate and coordinate virtually all aspects of plant growth and development.  In particular, the effects of such environmental stimuli as light, temperature, and even touch or gravity are typically transmitted by hormones (in effect, "chemical messengers").  There are at least five basic types of plant hormones.

"Auxins" typically promote organ formation, tissue organization, cell division, cell elongation, metabolism, translocation, growth movements, and "apical dominance" (of topshoots over sideshoots); but they typically inhibit leaf "abscission" (drop).

"Gibberellins" typically promote cell elongation, cell division, metabolism, and flowering; but they typically inhibit dormancy and organ formation.

"Cytokinins" typically promote cell division, cell enlargement, organ formation, and nutrient movement; but they typically inhibit dormancy, apical dominance, and death of tissues.

"Abscisic acid" typically promotes dormancy, flowering, abscission, and closure of the stomata; but it typically inhibits the action of gibberellins.

"Ethylene" gas typically promotes growth movements, abscission, death of tissues, and ripening of fruits (Ethylene is the gas used commercially to ripen bananas etc.).

ASEXUAL REPRODUCTION

Flowering plants can reproduce asexually, via vegetative body parts.

SEXUAL REPRODUCTION

In flowering plants, as in other plants, there is an "alternation of generations" in the life cycle, between "diploid" forms (with both sets of chromosomes) and "haploid" forms (with just one set of chromosomes).  As in other higher plants, the haploid "gametophytes" (producing the "gametes", sperms and eggs) are dependent upon the dominant, diploid "sporophytes" (the typical plant bodies).

Although most flowering plants are "monoecious" (producing both sperms and eggs), many flowering plants are "dioecious" (with separate sexes -- that is, with male and female plants).

Flowers -- the keys to angiosperm success -- arise on shoots from floral buds (evolved from leaf buds), which form at shoot tips or in axils (where leaves or side-branches meet the stem).  Flowers may be produced either alone or together, in well-defined "inflorescences".

Many plants -- the so-called "long day" and "short day" plants -- produce flowers only in response to the appropriate night-length (indicative of seasons in nature but able to be manipulated, as in greenhouses).

Mounted on the typically swollen "receptacle" of a "pedicel" (flower stalk), a flower is typically composed -- from outside to inside -- of a "perianth", several "stamens", and one to many "pistils" ("Complete" flowers have all these parts; "perfect" flowers have the parts of both sexes, that is, both stamens and pistils).  The perianth is composed of the "calyx" and the "corolla":  The calyx is the assemblage of "sepals" (floral bracts, typically green); the corolla is the assemblage of "petals" (which, like sepals, are modified leaves).  A stamen is composed of a typically bulbous "anther" (bearing pollen), atop a typically long "filament".  A pistil consists of one or more "carpels" (modified leaves), fused into a typically vase-like structure.  From top to bottom, a pistil is composed of a typically sticky "stigma" (which receives the pollen), at the end of a typically long "style" (through which the "pollen tube" will grow), at whose base is a typically swollen "ovary" (which eventually contains the seeds and ripens as the fruit).

The stamen is a "microsporophyll" (modified leaf).  Within the "pollen sacs" ("microsporangia") in the anthers, many "microspore mother cells" ("pollen mother cells") each produce four haploid "microspores", by "meiosis" (cell division that cuts the number of chromosomes in half).  Within each microspore forms two cells or free nuclei, by "mitosis" (cell division without a reduction in the number of chromosomes):  A "generative" cell or nucleus and a "tube" cell or nucleus.  The outer wall of the microspore hardens (and sometimes becomes sculptured), thus forming a grain of pollen (the young male gametophyte), which is released and disseminated.  In typical dicots and some monocots, showy, perfumed flowers attract insects, birds, bats, and other small animals, with whom the flowers may well have co-evolved (For example, ultra-violet markings on many flowers are visible to honey bees but not to us).  Typically, the animals pick up pollen as they drink from the floral "nectaries"; and as they visit other flowers, they coincidentally spread the pollen far and wide (increasing the variety and, thus, adaptability of the plant population).

In some dicots and such monocots as grasses, the flowers are not showy or perfumed; the pollen is typically spread by the wind.

As part of the pistil, the ovary consists of one or more carpels (sections), each a "megasporophyll" (modified leaf).  Typically growing on a stalk within a carpel of an ovary is an "ovule".  An ovule consists of a pair of sheath-like "integuments" (with a "micropyle" opening at their lower end) surrounding "nucellus" tissue (the "megasporangium").  Embedded within the nucellus are "megaspore mother cells", each of which produce four haploid "megaspores", by meiosis.  Three of the megaspores typically die; the surviving megaspore develops into a typically round "embryo sac" (the female gametophyte).  The embryo sac typically consists of an egg cell (near the micropyle end of the embryo sac), a pair of accompanying "synergid" cells (the evolutionary remnants of an "archegonium", as contains the egg in lower plants), a central "endosperm mother cell" (containing two haploid "polar" nuclei), and three "antipodal cells" (opposite the micropyle-end of the embryo sac).

"Viable" seeds (that is, those containing embryos) are occasionally formed "parthenogenetically" (that is, without sexual fertilization) in certain species; but in most species, seeds will not develop with "pollination" (transfer of pollen to the stigma) and sexual fertilization (of the egg).

Typically, after a pollen grain reaches the sticky stigma, it germinates into a "pollen tube", which grows through the style and into the ovary.  Typically, the generative cell, inside the grain of pollen, divides into two sperm nuclei, which (with the tube nucleus) travel within the growing pollen tube (the mature male gametophyte -- note that there is no separate "antheridium", as produces sperms in lower plants).  The pollen tube grows through the micropyle, into the ovule, and through the nucellus tissue, delivering the sperm nuclei directly to the embryo sac:  The sperms do not need to be flagellated and, in fact, are not (Unlike most of the sperms of lower plants, the sperms of flowering plants do not have to swim through environmental water -- flowering plants, like higher animals, are typically very well adapted to life out on dry land).

Unlike in any other plants, there is a "double fertilization" in flowering plants:  One sperm nucleus fertilizes the egg -- thus forming a diploid "zygote" (fertilized egg) -- and the other sperm nucleus fertilizes the two haploid nuclei in the endosperm mother cell -- thus forming a "primary endosperm cell", which is "triploid" (containing three sets of chromosomes).  The zygote develops into the embryo sporophyte.  The primary endosperm cell develops into the "endosperm", which (as the rest of the female gametophyte decomposes) nourishes the developing embryo (pushed by an attached "suspensor" to well within the endosperm).  Especially in grains, the endosperm may persist to eventually nourish the seedling (which will germinate after a period of dormancy); whereas in most dicots, the endosperm is entirely consumed by the developing embryo, which stores the food within its "cotyledons" (seedling leaves) -- two in dicots, one in monocots.  Although the nucellus is usually consumed by the developing embryo, it sometimes persists as a food-storing "perisperm"; and the integuments typically form a hard "seed coat" around the seed, borne within the ovary, which ripens as the fruit (typically developing only if the flower has been pollinated and the egg, fertilized).

A "simple fruit" matures from a single ovary, which may however be composed of several carpels (such as the segments of an orange).  A simple fruit may be fleshy (such as an apple) or dry; and a dry fruit may be either "dehiscent" (such as a bean pod), opening when ripe, or "indehiscent" (such as a walnut), not opening when the seed(s) inside mature.  An "aggregate fruit" (such as a raspberry) is composed of several ovaries growing separately within a single flower, borne on a single receptacle (which is actually the edible part of a strawberry -- its hard little "seeds" are actually the individual fruits); and a "multiple fruit" (such as a pineapple) is composed of several ovaries from several flowers growing together as one.

Typically, fleshy fruits attract hungry animals, which carry the seeds within their gut to new locations; whereas hard fruits (such as the grain of a grass plant or the winged pod of a maple tree) help spread the seeds in or on the fur or feathers of animals or on the currents of wind or water.

Typically, the dormancy of a seed is broken (that is, its germination is triggered) by an environmental condition -- or a sequence of environmental conditions -- that signals a favorable place and/or time:  Factors may include light, temperature, moisture, and/or abrasion.  In particular, abrasion of a seed coat typically occurs in nature as a seed is washed downstream, typically over rocks, which allows chemical inhibitors, such as the traces of cyanide found in almond or apple seeds, to be leached away:  Like Johnnie Appleseed, this natural process "plants" the seeds far and wide.

All in all, flowering plants have become the dominant terrestrial flora on Earth primarily because of their wonderful adaptations for reproductive success:  Flowers -- enhancing cross-pollination and, thus, genetic diversity -- and fruits -- enhancing dispersal of seeds.

Representatives

Green Plants (Viridaeplantae)

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