Taxonomy of Angiosperms#Part II # Dicotyledon family # Brassicaceae#Botany 4th Sem #TU

           Fig :Floral diagram of Brassica nigra and floral formula of the family Brassicaceae.

Brassicaceae 

            The  family Brassicaceae  is also known as Mustard family  and previously termed as Cruciferae due to cruciferous petats of it's flowers.It has 350 and 2500 genera and species respectively.

   Systematic position: 

Division        Angiospermia

Class             Dicotyledons

Subclass       Polypetalae

Series            Thalamiflorae

Cohort           Parietales

Family            Brassicaceae

    Diagnostic characters:

1. Plants herbs with watery sap.

2. Leaves simple , exstipulate, radical and cauline.

3. Inflorescence raceme.

4. Flowers ebractate, bisexual, actinomorphic.

5. Sepals 2+2,arranged in two whorls.

6.Petals 4 , cruciform.

7. Stamens 2+4, tetradynamous.

8.Bicarpellary, one-celled but appears two celled due to false replum , placentation parietal.

9. Fruit siliqua or siliqula .

General characteristics: 

1. Plants annual (Brassica, Capsella ) or biennial herb, glabrous or hairy with watery sap.

2.Leaves simple (pinnately compound in Cardamine, Loxostemon),sessile, alternate or partially opposite,cauline ,radical and reticulate venation.

3.Infloresence raceme ( corymb in Iberis).

4. Flowers pedicellate, ebractate, bisexual, hypogynous, actinomorphic ( zygomorphic in Iberis, Teesdalia), regular ( irregular in Lepidium), tetramerous.

5.Sepals2+2, polysepalous,two sepals antero-posterior , two lateral , arranged in two dimerous whorls, caducous  and imbricate.

6.Petals 4, polypetalous, cruciform having claw and limb( in Iberis anterior 2 petals are large) , petals absent in Coronopus ,  valvate.

7. Stamens 2+4, tetradynamous,outer 2 short   and inner 4 long , alternipetalous , honey glands at base, anthers 2-celled , introrse (exceptions Lepidium A2, Coronopus A2, Cardamine hirsuta A4, Nasturtium A4 ,Megacarpea A16).

8. Carpels2(4 in Tetrapoma, Holargidium) , ovary superior, unilocular but becomes bilocular due to false replum , placentation parietal, ovules many, campylotropous , style short , stigma 2-lobed .

9.Fruit :Siliqua ( Brassica ) or siliquala (Alssum).

Economic plants:

1 Edible oil from Brassica nigra , Brassica campestris , etc.

2. Vegetable: Brassica oleracea botrytis = cauliflower, Brassica oleracea capitata =  cabbage  Raphanus sativus =radish.

3.Ornamental: Iberis .