HOW DO PLANTS DEFEND THEMSELVES?

Plants cannot escape from hungry plant-eaters, but they have evolved a wide range of defenses. Some have thorns or spines that cut into an animal’s skin and will pierce its mouth if eaten. Others produce chemicals that taste terrible and may be poisonous. Some have tiny hairs on their leaves that stop leaf-eating insects from reaching the leaf’s surface.

LICHENS

A lichen is not a single organism, but a combination of a fungus and a green alga. Lichens exist in extreme climates, from dry deserts to the icy Arctic. They grow on surfaces such as rock, bark, and soil.

HOW DO FUNGI AND ALGAE LIVE IN LICHENS?

The fungus forms an outer layer that protects the alga beneath from drying out and shields it from harmful amounts of light. The alga makes its own food by photosynthesis, and shares it with the fungus. In return, the fungus supplies the alga with essential minerals, such as nitrogen. This beneficial relationship between two different species is called symbiosis.

CONIFERS

Trees and shrubs whose seeds develop in woody cones are called conifers. The 550 species include pines, firs, and cedars. Conifers form dense forests in colder, northern regions. Most keep their leaves all year long.

HOW DO CONIFERS PRODUCE SEEDS?

Conifers have male and female cones. The male cones release pollen grains (male sex cells), which are blown by the wind. If pollen lands on the female cones, it fertilizes the female egg cells. The fertilized eggs develop into seeds. After one or two years, when the seeds have matured, the female cone opens up. It drops winged seeds, which germinate wherever they land.

WHY DO SOME CONIFERS HAVE NEEDLE-SHAPED LEAVES?

Leaves shaped like needles help conifers survive in cold, harsh climates. The leaves are tough and coated with a waxy outer coat, or cuticle. The narrow shape, toughness, and cuticles all help the leaves withstand high winds and extreme temperatures. They also reduce water loss.

DO OTHER PLANTS HAVE CONES?

A group of plants called cycads have large seed-producing cones that can grow to more than 22 in (55 cm) long. They have sturdy trunks topped by long, divided leaves, and look more like palm trees than conifers. Cycads grow in tropical and subtropical regions. They are descended from a group of plants that flourished 250 million years ago. Today, there are 140 species of cycads.

CLASSIFICATION OF NON-FLOWERING PLANTS

There are 11 main phyla of non-flowering plants:

Liverworts

Mosses

Hornworts

Whisk ferns

Club mosses

Horsetails

Ferns

Conifers

Cycads

Ginkgo

Gnetophytes.

The last four form a group called gymnosperms—they produce seeds instead of spores.

SPORES

Non-flowering plants reproduce by releasing large numbers of tiny spores. These minute organisms consist of one or a few cells inside a tough coat.

WHY IS SPORE DISPERSAL IMPORTANT?

Many non-flowering plants rely on wind to carry their reproductive spores as far away as possible. This reduces competition with the parent plant for light, water, and important nutrients. If a spore lands in a damp place, it germinates (sprouts) and grows into a new plant.

CONIFERS

Trees and shrubs whose seeds develop in woody cones are called conifers. The 550 species include pines, firs, and cedars. Conifers form dense forests in colder, northern regions. Most keep their leaves all year long.

HOW DO CONIFERS PRODUCE SEEDS?

Conifers have male and female cones. The male cones release pollen grains (male sex cells), which are blown by the wind. If pollen lands on the female cones, it fertilizes the female egg cells. The fertilized eggs develop into seeds. After one or two years, when the seeds have matured, the female cone opens up. It drops winged seeds, which germinate wherever they land.

NON-FLOWERING PLANTS

Mosses, ferns, and their relatives are plants that do not produce flowers but reproduce by means of SPORES. Most live in shady or damp habitats. CONIFERS are non-flowering plants that reproduce by making seeds.

HOW DO FERNS GROW?

The stem, or rhizome, of a fern grows horizontally through the soil. Tiny curled-up fronds (leaves) grow from small buds on the rhizome. The buds unroll and the frond expands. The fronds of some ferns grow 20 ft (6 m) long, but others reach only 1/2 in (13 mm).

HOW DOES MOSS LIVE WITHOUT ROOTS?

Most mosses grow in short clumps, or cushions. They do not have true roots, but short, slender growths, called rhizoids. Rootlike rhizoids anchor moss to soil, rock, or bark, but do not draw up water. Instead, leaves absorb moisture in the air.

The leafy tips of mosses produce male and female sex cells. Male sex cells swim through water on the surface of the plant to reach and fertilize female cells. Fertilization produces a stalked sporophyte, or spore capsule, that scatters spores into the air.

Grass Flower

The picture below shows a close-up of a grass inflorescence -- in this case the grass is a species of bamboo growing near my home. In the top, left quarterof the picture  you see a spikelet consisting of three or four grass flowers (called florets) growing together. From each flower you see some stamens dangling out, and of course stamens are the male parts of a flower. The very slender, white strands emerging from the flowers are the stamens' filaments, and at the bottom of each filament you see the yellowish anthers, from which pollen is shed.

croton - pokok puding

Crotons have little white puffy flowers on long flimsy stems.  They don't seem to last very long, especially in the humidity of the greenhouse.  The flowers eventually produce seeds pods that look a little like daylily pods.

Lemongrass

Lemon grass, Cymbopogon citratus and Cymbopogon flexuosus, is an unusual tropical grass as an essential flavoring in South East Asian cooking. Its bright lemony scent is used in drinks, curries and soups. It is delicious in tea with cloves. It's rich in vitamin A. Its oil also has many industrial and medicinal uses.

Lemon grass is native to India, Sri Lanka, Malaysia and Indonesia. C. citratus is referred to as West Indian, C. flexuosus as East Indian, Cochin or Malabar. Other common names are fever grass or citronella grass. There are over 50 species in the genus. Both of the common species are fast growing perennials that grow to 3 to 6 feet tall and 3 feet wide. They have long, light green leaves and inconspicuous flowers.