[Biology Class Notes] on Asteraceae, Brassicaceae, Poaceae – Angiosperm Families Pdf

• Asteraceae

• Brassicaceae

• Poaceae

Asteraceae

Characteristics of Asteraceae

They have the following characteristic features:

1. These are herbs, shrubs or trees. Most of them are xerophytes, hydrophytes and semi-aquatic.

2. Taproots are modified into tubers.

3. The stem could be erect, hairy, woody or prostrate. It might sometimes contain latex.

4. The leaves may be radical, petiolate, exstipulate,

5. Flowers are tubular or ligulate, bisexual or unisexual, usually dithecous, filament free with united anthers.

6. Androecium is absent.

7. Gynoecium is either absent or present.

8. The seed is endospermic.

9. The fruit produced is cypsela.

Economic Importance of Asteraceae

Food

Family Asteraceae is an important source of food. The leaves and roots of a couple of angiosperms like garden lettuce and Jerusalem artichoke are edible.

Oil

The seeds of angiosperms are a crucial source of oil.

Medicines

Most of the plants that belong to the Asteraceae family have some of the best medicinal values. For eg., Solidago is employed in dropsy, artemisia yields santonin, the juices and roots of a couple of plants are utilized in bowel disorders and have a cooling effect..

Rubber

Taraxacum and Solidago leavenworthii are a crucial source of rubber.

Insecticide

The capitula of Chrysanthemum roseum is dried and its powder is employed as an insecticide.

Brassicaceae

Characteristics of Brassicaceae

Following are the important characteristics of family Brassicaceae:

1. These are generally herbs, annuals, biennials, or shrubs.

2. The taproots are swollen due to food storage.

3. The stem is erect, herbaceous, and rarely woody.

4. Leaves are alternate, opposite, simple and exstipulate

Economic Importance of Brassicaceae

Food

The plants of this family are cultivated as vegetable crops. For eg., Brassica oleracea var. Botrytis, Brassica oleracea var. Caulorapa.

Oil

The seeds of the plants of these families are used to extract mustard oil that is extensively used in cooking. For eg., Brassica campestris

The cake left behind after the extraction of oil is employed as cattle feed and fertilizer.

Medicines

The leaves and shoots of plants are utilized in asthma, cough and bleeding piles. They also act as an appetizer and stimulant. The seeds are wont to treat bronchitis and fever. The flowers help in paralysis and impotency.

Ornamentals

Few plants like Iberis amara, Hesperis, Alyssum, bear beautiful flowers and are used for ornamental purposes.

Poaceae

Characteristics of Poaceae

Following are the important characteristics of Poaceae family:

1. It might be herbs or shrubs, annuals or perennials, and sometimes tree-like.

2. The roots are often fibrous, adventitious, branched or stilt.

3. The stem could also be underground as in rhizomes, cylindrical with conspicuous nodes and internodes, woody or herbaceous.

4. The leaves are alternate, simple, exstipulate, and distichous. The leaf base forms a tubular sheath.

5. The seeds are endospermic and monocotyledonous.

6. Fruits include caryopsis, nuts or berry.

Economic Importance of Poaceae

Food

The plants of this family are a crucial food source. For eg., cultivated rice , common wheat , cereal oat (oats), corn (Maize).

Grasses like Panicum, Bermuda grass , Cymbopogon, and Poa are used as fodder.

Sugar

Jaggery and sugar are obtained from Saccharum officinarum.

Building Material

Species of Bambusa are used for scaffolding and thatching of huts.

Aromatic Plants

Many sorts of grass like Vetiveria zizanioides yield scented oil from its roots. The roots are also used to weave curtains.

Medicines

Plants such as Phragmites karka, Claviceps purpurea, Cymbopogon schoenanthus have medicinal values.