Angiosperm.html: 30_13mMonocotsEudicots-L.jpg
Monocot characteristics:
Angiosperm_cycle.html: 30_10AngiospermLifeCycle.jpg
The life cycle of an angiosperm.
Coniferophyta.html: 30_04aGymnospermConiferophyta.jpg
Coniferophyta.
Pseudotsuga menziesii (Douglas fir) produces more timber than any other American forest species.
Pinus longaeva (Bristlecone pine) can reach ages of more than 4,600 years.
This Sequoia giganteum (Giant Sequoia) weighs about 2,500 metric tons (about 24 blue whales, or 40,000 people).
The "berries" of Juniperus communis (Common juniper) are ovule-producing cones
consisting of fleshy sporophylls.
Coniferophyta2.html: 30_04aGymnospermConiferophyta2.jpg
Coniferophyta.
Pinus longaeva (Bristlecone pine) lives in the White Mountains of California,
and can reach ages of more than 4,600
years.
This Sequoia giganteum (Giant Sequoia) weighs about 2,500 metric tons (about 24 blue whales, or 40,000 people).
The related Sequoia sempervirens (Coast Redwood) can grow to more than 110 meters, 1/4 the height of the Sears tower.
Cycadophyta.html: 30_04aGymnospermCycadophyta.jpg
Phylum Cycadophyta. Cycads
have large cones and palmlike leaves and thrived during the Mesozoic era - "Age of Cycads" ("Age of Dinosaurs").
Gingkophyta.html: 30_04aGymnospermGingkophyta.jpg
Gingko biloba is the only extant species of phylum Gingkophyta.
Landscapers usually plant only pollen-producing male trees because the fleshy seeds smell rancid as they decay.
Gnetophyta.html: 30_04aGymnospermGnetophyta.jpg
Gnetophyta.
Gnetophytes live in tropical and desert environments.
Gymnosperm.html: 30_UN593PlantPhylogeny.jpg
Gymnosperm_cycle.html: 30_06PineLifeCycle.jpg
Life cycle of a conifer (a gymnosperm).
dicot.html: 30_dicot.jpg
dispersal.html: 30_09FruitDispersal.jpg
Fruit adaptations that enhance seed dispersal.
Wings enable maple fruits to be carried by the wind.
Seeds within berries and other fruits are dispersed in animal feces.
The barbs of cockleburs facilitate seed dispersal by allowing the fruits to “hitchhike” on
animals.
flower.html: 30_07FlowerStructure_L.jpg
The structure of a flower.
Sepals enclose the flower, petals may be brightly colored to attract pollinators.
Stamens produce pollen, and carpels contain ovaries.
An ovary caontains several ovules which develop into seeds after fertilization.
The stamens collectively are called "androecium",
while the carpels are called "gynoecium".
A complete flower has all four basic floral organs.
A perfect flower contains both male and female structures.
_Vid_Campbell7e/FlowerTimeLapse-V.swf
fruit.html: 30_08Fruit.jpg
The wall of the fertilized ovary thickens into layers of pericarp surrounding a fruit.
Fleshy fruits,
such as tomato (2 soft layers),
grapefruit (firm outer layer, soft inner layer),
and nectarine (soft outer, firm inner pit),
attract animals which eat the fruit and aid in dispersal of the indigestible seeds.
Dry fruits,
such as milkweed and hazelnut,
are often adapted for dispersal by wind or water, or by animal carriers.
gameto.html: 30_02GametoSporophyteSeedless.jpg
Bryophytes have life cycles dominated by gametophytes.
Seedless vascular plants have sporophyte-dominated life cycles,
with small, free-living gametophytes.
Gametophyte reduction continued further in seed plants,
becoming microscopic and dependent upon the sporophyte for nutrition and
protection.
gametophyte.html: 30_02GametoSporophyteSeeded.jpg
Seed plants are heterosporous.
Different spores produce reduced male and female
gametophytes, which in turn produce gametes.
The tiny gametophytes are dependent upon the sporophyte for nutrition and protection.
megaspore.html: 30_03OvuleToSeedA.jpg
Unfertilized ovule.
In the ovule of a pine (a gymnosperm),
a fleshy megasporangium is surrounded by a protective integument. (Angiosperms have two integuments.)
microspore.html: 30_06PineLifeCycle_1-L.jpg
Male gametophytes.
Pollen cones contain microsporangia
where microsporocytes undergo meiosis to produce microspores, which develop into
male gametophytes (pollen grains).
monocot.html: 30_monocot.jpg
ovule.html: 30_03OvuleToSeedB.jpg
Fertilized ovule.
A megaspore develops into a multicellular female gametophyte.
A pollen grain (male gametophyte) enters through the micropyle, and develops
a pollen tube in which the sperm can travel.
pollination.html: 30_13FlowerPollinator.jpg
A flower pollinated by honeybees. This honeybee is harvesting pollen and nectar (a sugary solution secreted by flower glands) from a Scottish broom flower. The flower has a tripping mechanism that arches the stamens over the bee and dusts it with pollen, some of which will rub off onto the stigma of the next flower the bee visits. _Vid_Campbell7e/BeePollinating-V.swf |
A flower pollinated by hummingbirds. The long, thin beak and tongue of this rufous hummingbird enable the animal to probe flowers that secrete nectar deep within floral tubes. Before the hummer leaves, anthers will dust its beak and head feathers with pollen. Many flowers that are pollinated by birds are red or pink, colors to which bird eyes are especially sensitive. |
A flower pollinated by nocturnal animals. Some angiosperms, such as this cactus, depend mainly on nocturnal pollinators, including bats. Adaptations of such plants include large, light-colored, highly fragrant flowers that nighttime pollinators can locate. |
seed.html: 30_03OvuleToSeedC.jpg
Gymnosperm seed.
After fertilization, the ovule develops into a seed
A seed consists of an embryo along with its
food supply packaged in a protective seed coat derived from the integument.
seed_plants.html: 30_01SeedPlantsMeds.jpg
A Sampling of Medicines Derived from Seed Plants.
Seed plants provide many products including food, wood, and many medicines.