Basically Botany

‘Starter’ Plants

• Stinkwood• Pepperwood• Rangiora• Crown fern…

Parts of a Plant

Pollination

Wind vs Insect Pollinated Flowers

Fuchsia Flowers

The flowers are very decorative; they have a pendulous "teardrop" shape and are displayed in profusion throughout the summer and autumn, and all year in tropical species. They have four long, slender sepals and four shorter, broader petals; in many species the sepals are bright red and the petals purple (colours that attract the hummingbirds that pollinate them), but the colours can vary from white to dark red, purple-blue, and orange. A few have yellowish tones, and recent hybrids have added the colour white in various combinations. The ovary is inferior and the fruit is a small (5–25 mm) dark reddish green, deep red, or deep purple, edible berry, containing numerous very small seeds. Many people describe the fruit as having a subtle grape flavour spiced with black pepper.

Fuchsia hybrida Fuchsia excorticata

Seed Dispersal• Why?

– Plants spread their seeds to minimise competition (eg for water) amongst seedlings

– And to reduce the chance of the whole species being wiped out by a disaster.

• How?– Water: floating seeds transported by streams, ocean currents. Eg

coconut, kowhai– Explosion: seed pods rapidly open and fling seeds out. Eg broom, gorse– Wind: small light seeds, with structures that catch the wind are

transported downwind. Eg dandelion, thistle– Eaten by animal: fleshy tasty fruit eaten and animal egests seed out in

a new location. Eg apple, apricot– Caught on animal: seeds have hooks, catch on fur, fall off in new place.

Eg bidibid

Poor mans orchid

Dandelion

Thistledown (aka fairy)Kowhai

bidibid

Hook grass

Seed Structure & Germination

External Leaf Adaptations for PhotosynthesisStructure FunctionWide blade Thin leaf Vein network Green colour Pores in leaf Waxy surface Strong petiole

Leaf Cross Section

Key: 1) cuticle 2) upper epidermis 3) palisade mesophyll 4) spongy mesophyll 5) lower epidermis 6) stoma 7) guard cells 8) xylem 9) phloem 10) vascular bundle

Internal Leaf Adaptations for PhotosynthesisAir space - intercellular gaps within the spongy mesophyll. These gaps are filled with gas that the plant uses (carbon dioxide - CO2 ) and gases that the plant is expelling (oxygen - O2, and water vapour).Cuticle - the waxy, water-repelling layer on the top and bottom surfaces of a leaf; it helps keep the leaf from dying out (and protects it from invading bacteria, insects, and fungi). The cuticle is secreted by the epidermis. Label the cuticle on the top and bottom of the leaf.Guard cell - one of a pair of sausage-shaped cells that surround a stoma (a pore in a leaf). Guard cells change shape (as light and humidity change), causing the stoma to open and close.Lower epidermis - the waxy skin (outermost cells) on the underside of a leaf, usually one cell thick; it keeps the leaf from drying out.Mesophyll - the chlorophyll-containing leaf tissue located between the upper and lower epidermis. These cells convert sunlight into usable chemical energy for the plant.

Palisade mesophyll - a layer of elongated cells located under the upper epidermis. These cells contain most of the leaf's chlorophyll, converting sunlight into usable chemical energy for the plant.Spongy mesophyll - the layer below the palisade mesophyll; it has irregularly-shaped cells with many air spaces between the cells, this allows gases to circulate. These cells contain some chlorophyll (less light gets to here). The spongy mesophyll cells communicate with the guard cells (stomata), causing them to open or close, depending on the concentration of gases.Stoma - (plural stomata) a pore (or opening) in a leaf where water vapour and other gases leave and enter the plant. Stomata are formed by two guard cells that regulate the opening and closing of the pore. Generally, many more stomata are on the bottom of a leaf than on the top.Upper epidermis - the protective, outer layer of cells on the upper surface of a leaf, usually one cell thick. The epidermis secretes the waxy cuticle which reduces water loss. The upper epidermis contains some guard cells (but fewer than the lower epidermis).Vein (vascular bundle) - Veins provide support for the leaf and transport both water and minerals (via xylem tubes) and food energy (via phloem tubes) through the leaf and on to the rest of the plant.

Xylem & PhloemBoth are transport tissues

Xylem• Transports water, micronutrients from roots up to rest of plant• Forms woody layer in woody plants• Mostly dead cellsPhloem• Transports sugars, metabolic products from leaves down to

rest of plant• Living cells

Multiple cross sections of a flowering plant stem showing primary and secondary xylem and phloem

Phloem / Xylem Celery Experiment

phloem

*Ringbarking aka girdling• Because phloem tubes sit on the outside of

the xylem in most plants, a tree or other plant can be effectively killed by stripping away the bark in a ring on the trunk or stem. With the phloem destroyed, nutrients cannot reach the roots, and the tree/plant will die. Trees located in areas with animals such as beavers are vulnerable since beavers chew off the bark at a fairly precise height. This process is known as girdling, and can be used for agricultural purposes. For example, enormous fruits and vegetables seen at fairs and carnivals are produced via girdling. A farmer would place a girdle at the base of a large branch, and remove all but one fruit/vegetable from that branch. Thus, all the sugars manufactured by leaves on that branch have no sinks to go to but the one fruit/vegetable, which thus expands to many times normal size.

Photosynthesis

Plant Pigment Chromotography

Respiration

Transpiration

*Asexual & Sexual Reproduction