PLANT BIOLOGICAL SYSTEMS AND NEEDS Chapter 12

Kinds of plants Plants are the basis of the food chain for all living things. Botany – the science of the study of plants Over 280,000 species of plants.

Angiosperms Angiosperm is a plant with enclosed seeds. More than half of all living plants are classified as flowering plants or angiosperms Angiosperms are the most highly evolved of the plants Each flower usually contains both pollen and ovules Pollination can be completed by wind, insects, or by the plant itself Cotyledons are the seedling leaves when the seed first sprouts or germinates Angiosperms are either monocots (one cotyledon) or dicots (two).

Monocots Leaves have parallel veins Leaves are usually long and blade-like Stems tend to be non-woody with scattered vascular bundles Roots tend to be fibrous Flowers have 3 petals or multiples of 3 Grasses are the most important monocots.

Dicots Dicots have branching veins Leaves are typically compound or deeply lobed Stems tend to be woody Roots tend to be woody and widely branched Flowers have petals in groups of 4 or 5 Deciduous trees (lose leaves) are among the most important dicots to F&W.

Conifers Conifers typically have evergreen needles for leaves and produce cones Includes members of the pine, fir, cedar, and spruce families They are so well-adapted, they have remained relatively unchanged for 300 million years.

Major Plant Parts Root – anchors the plant and absorbs water and nutrients from the soil Shoot – the above-ground portion of the plant that provides support, conducts water and other materials within the plant, and manufactures food by photosynthesis. Node – place on a stem where leaves are attached Vegetative stage – young rapidly-growing, non-flowering stage Reproductive stage – when a plant starts producing flowers, fruits, and seed.

Plant Life Cycles Annuals – short-lived plants in which the entire life cycle, from germination to seed production, takes place in one growing season Biennials – have a two-year life cycle; they do not normally bloom until the second season after the seed is planted Perennials – live from year to year; generally divided into two categories – woody and herbaceous.

Annuals

Biennials

Perennials

Plant Reproduction Vegetative reproduction – asexual reproduction, vegetative propagation; can multiply in more ways than just by seed Usually by runners (stolons), rhizomes (thick, underground stem), and horizontal roots Sexual Reproduction – seeds are produced in flowers; stamen is male reproductive structure; pistil is female reproductive structure Monoecious – staminate and pistillate flowers produced on same plant Dioecious – staminate and pistillate flowers produced on separate plants

Vegetative Propagation

Monoecious plants

Dioecious Plants