39 Insightful Publications
- Understand and familiarise yourself with the descriptive terms for the habit of the plant, its root system, stem and leaves, inflorescence, and flowers.
- Describe the vegetative and floral features of the plant.
- Observe the longitudinal section of the flowers under a hand lens.
- The stamen and pistil are dissected, and the internal features are observed under a compound microscope.
- Based on the observations, the floral diagram and floral formula are determined for the two plant specimens.
The details of the observations of the two plant specimens are given below:
The vegetative and floral characteristics of the two plant specimens are given in the below table:
| Plant Parts | Characters |
|---|---|
| Root | Lathyrus japonicus and Pisum sativum both have tap root systems with root nodules containing nitrogen-fixing Rhizobium bacteria. |
| Stem | In both plants, the stem is green, herbaceous, tender, and weak. Tendrils are present. |
| Leaves | The leaves are stipulated and show reticulate venation. The leaves of Pisum sativum are imparipinnately compound, with the terminal leaf modified into leaf tendrils. |
| Inflorescence | Racemose |
| Flower | Flowers are bracteate, bracteolate, bisexual, and pentamerous. The symmetry is zygomorphic. |
| Calyx | Both Pisum sativum and Lathyrus japonicus possess five sepals that are gamosepalous. |
| Corolla | In Pisum sativum, the corolla is white or purple in colour. The corolla of Lathyrus exhibits the same characteristics except that its petals are blue or purple in colour. In both plants, the corolla is papilionaceous and shows imbricate aestivation. |
| Androecium | In both plants, the flowers are monocarpellary. The ovary is superior and unilocular; many ovules are within each locule. The arrangement of ovules within the ovary shows marginal placentation. |
| Gynoecium | In both plants, the flowers are monocarpellary. The ovary is superior and unilocular; there are many ovules within each locule. The arrangement of ovules within the ovary shows marginal placentation. |
| Fruit | In both plants, the fruits are of the legume type. |
| Seed | Non-endospermic seeds |
The floral formula of the Fabaceae family: Br, Brl, %, 
The floral diagram is 
FAQs on Fabaceae
Q.1: What are the main characters of the Family Fabaceae?
Ans: The presence of root nodules is the main character of the family Fabaceae.
Q.2: Define roof nodules.
Ans: Root nodules are found on the secondary roots of plants, especially legumes, which establish a symbiotic relationship with nitrogen-fixing Rhizobium bacteria.
Q.3: Define papilionaceous corolla.
Ans: A papilionaceous corolla is a form of corolla found in the Fabaceae family of flowers. It is distinguished by five petals organized in a butterfly shape. The uppermost petal is known as the standard, while the two lateral petals are known as wings. The two lowest petals fuse together to form a keel.
Q.4: What is basifixed anther?
Ans. An anther that is attached to the filament at the base.
Q.5: Difference between floral diagram and floral formula.
Ans: A floral diagram is a graphical representation of the structure of a flower. It depicts the number, arrangement, and fusion of floral organs. A floral formula, on the other hand, is an expression that, in the form of an equation, summarizes the information presented in the floral diagram. The floral diagram cannot depict the position of the ovary on the thalamus, but the floral formula can. Placentation, which refers to the arrangement of ovules in the ovary, can be depicted in a floral diagram but not in a floral formula.
JEE Main