Concept 30.1: The reduced gametophytes of seed plants are protected in ovules and pollen grains In addition to seeds, the following are common to all seed plants: – Reduced gametophytes – Heterospory – Ovules – Pollen
LE 30-2 Sporophyte (2n) Gametophyte (n) Sporophyte dependent on gametophyte (mosses and other bryophytes) Gametophyte (n) Sporophyte (2n) Large sporophyte and small, independent game- tophyte (ferns and other seedless vascular plants) Microscopic female gametophytes (n) in ovulate cones (dependent) Microscopic male gametophytes (n) in inside these parts of flowers (dependent) Sporophyte (2n), the flowering plant (independent) Microscopic male gametophytes (n) in pollen cones (dependent) Microscopic female gametophytes (n) in inside these parts of flowers (dependent) Sporophyte (2n), (independent) Reduced gametophyte dependent on sporophyte (seed plants: gymnosperms and angiosperms)
LE 30-4ad Gnetum. This genus includes about 35 species of tropical trees, shrubs, and vines, mainly native to Africa and Asia. Their leaves look similar to those of flowering plants, and their seeds look somewhat like fruits.
LE 30-4ae Ephedra. This genus includes about 40 species that inhabit arid regions throughout the world. Known in North America as “Mormon tea,” these desert shrubs produce the compound ephedrine, commonly used as a decongestant.
LE 30-4af Welwitschia. This genus consists of one species Welwitschia mirabilis, a plant that lives only in the deserts of southwestern Africa. Its strap like leaves are among the largest known.
LE 30-4ba Douglas fir. “Doug fir” (Pseudotsuga menziesii) provides more timber than any other North American tree species. Some uses include house framing, plywood, pulpwood for paper, railroad ties, and boxes and crates.
LE 30-4bb Pacific yew. The bark of Pacific yew (Taxa brevifolia) is a source of taxol, a compound used to treat women with ovarian cancer. The leaves of a European yew species produce a similar compound, which can be harvested without destroying the plants. Pharmaceutical companies are now refining techniques for synthesizing drugs with taxol-like properties.
LE 30-4bc Bristlecone pine. This species (Pinus longaeva), which is found in the White Mountains of California, includes some of the oldest living organisms, reaching ages of more than 4,600 years. One tree (not shown here) is called Methuselah because it may be the world’s oldest living tree. In order to protect the tree, scientists keep its location a secret.
LE 30-4bd Sequoia. This giant sequoia (Sequoiadendron giganteum), in California’s Sequoia National Park weighs about 2,500 metric tons, equivalent to about 24 blue whales (the largest animals), or 40,000 people. Giant sequoias are the largest living organisms and also some of the most ancient, with some estimated to be between 1,800 and 2,700 years old. Their cousins, the coast redwoods (Sequoia sempervirens), grow to heights of more than 110 meters (taller than the Statue of Liberty) and are found only in a narrow coastal strip of northern California.
LE 30-4be Common juniper. The “berries” of the common juniper (Juniperus communis), are actually ovule- producing cones consisting of fleshy sporophylls.
LE 30-4bf Wollemia pine. Survivors of a confer group once known only from fossils, living Wollemia pines (Wollemia nobilis), were discovered in 1994 in a national park only 150 kilometers from Sydney, Australia. The species consists of just 40 known individuals two small groves. The inset photo compares the leaves of this “living fossil” with actual fossils.
LE 30-8 Tomato, a fleshy fruit with soft outer and inner layers of pericarp Ruby grapefruit, a fleshy fruit with a hard outer layer and soft inner layer of pericarp Milkweed, a dry fruit that splits open at maturity Walnut, a dry fruit that remains closed at maturity Nectarine, a fleshy fruit with a soft outer layer and hard inner layer (pit) of pericarp
LE 30-9 Wings enable maple fruits to be easily carried by the wind. Seeds within berries and other edible fruits are often dispersed in animal feces. The barbs of cockleburs facilitate seed dispersal by allowing these fruits to hitchhike on animals.
LE 30-12aa Amborella trichopoda Water lily (Nymphaea “Rene Gerald”) Star anise (Illicium floridanum) BASAL ANGIOSPERMS
LE 30-12ab Southern magnolia (Magnolia grandiflora) HYPOTHETICAL TREE OF FLOWERING PLANTS MAGNOLIIDS Amborella Star anise and relatives Water lilies Magnoliids Monocots Eudicots
LE 30-12ba Orchid (Lemboglossum rossii) Monocot Characteristics One cotyledon Embryos Two cotyledons Eudicot Characteristics California poppy (Eschscholzia california) EUDICOTSMONOCOTS
LE 30-12bb Pygmy date palm (Phoenix roebelenii) Veins usually parallel Vascular tissue scattered Stems Pyrenean oak (Quercus pyrenaica) EUDICOTSMONOCOTS Leaf venation Vascular tissue usually arranged in ring Veins usually netlike
LE 30-12bc Dog rose (Rosa canina), a wild rose Root system usually fibrous (no main root) Roots Lily (Lilium “Enchantment”) EUDICOTSMONOCOTS Taproot (main root) usually present
LE 30-12bd Barley (Hordeum vulgare), a grass Floral organs usually in multiples of three Pollen Zucchini (Cucurbita Pepo), female (left), and male flowers EUDICOTSMONOCOTS Pollen grain with three openings Stigma Ovary Anther Filament Floral organs usually in multiples of four or five Pollen grain with one opening Flowers Pea (Lathyrusner vosus, Lord Anson’s blue pea), a legume