Biology Experiment: To Study And Describe Flowering Plants of Families Solanaceae, Fabaceae and Liliaceae
The Solanaceae, sometimes referred to as nightshades, is a family of flowering plants that includes annual and perennial herbs, vines, lianas, epiphytes, shrubs and trees. It comprises several crops, medicinal plants, spices, weeds, and ornamentals.
Fabaceae is also known as Leguminosae or Papilionaceae since it belongs to the pea or legume family. It comprises several economically important plants.
Liliaceae, also referred to as the lily family, mainly comprises ornamental plants such as lilies and tulips and medicinal plants such as Aloe vera, Colchicum, etc.
Table of Contents
Aim
Requirements
Theory
Procedure
Observation
Result
Precaution
Aim
To study and describe flowering plants of families Solanaceae, Fabaceae and Liliaceae. Draw neat labelled diagrams.
Requirements
Pisum sativum, Allium cepa and Petunia nyctanginifolia plant specimens, slides, water, beaker, blade, dissecting microscope, Petri dishes, compound microscope, etc.
Theory
Identification, nomenclature, and classification of organisms are all topics covered by taxonomy. For classifying angiospermic plants, the Bentham and Hooker system of classification is commonly used. Plant identification in the field mostly depends on floral qualities and morphological characteristics.
Procedure
Select a flower containing all parts.
Observe each part of the flower.
With your hand's help, carefully remove a flower's sepals and petals.
With the help of a scalpel, remove the anther.
Cut the stamen and anther in half with the scalpel.
Remove the pistil from the flower and observe the stigma, style and ovary.
Take each separated part on a slide and observe it under the microscope.
Observations
Determine the plant's family by comparing the characters of different families
Features of the Solanaceae Family
Petunia nyctanginifolia.
Floral features
Racemose, a terminal or axillary raceme, and Cymose, a solitary inflorescence, are both in the Solanaceae family.
The Solanaceae family includes plants with five sepals under the calyx, valvate aestivation, and gamosepalous flowers.
The corolla in the Solanaceae family has five petals, valvate aestivation, and is gamopetalous (having a corolla made up of a single group of petals)
The corolla is infundibuliform
Five epipetalous stamens with basifixed anthers make up the androecium.
Bicarpellary, superior ovary, bilocular, axile placentation, syncarpous gynoecium, capitate stigma
Floral formula: Br, ⊕⚥ K(5),C(overline{(5A)})5, G(2)
Features of the Fabaceae Family
Pisum sativum
Floral features
The racemose inflorescence is found in the Fabaceae.
The calyx is gamosepalous, contains 5 sepals, is campanulate, and has imbricate aestivation.
Fabaceae family includes plants with five petals (1 standard, 2 wings,2 keels united, and keels shorter than wing ) enclosing the stamen and pistil. Imbricate aestivation.
The androecium comprises 10 stamens which are grouped into two bundles in a 10+2 fashion. Anthers are basifixed and bilobed.
The gynoecium is the monocarpellary, unilocular, superior ovary, single, hairy-stigmata, containing marginal placentation.
Floral formula: % ⊕⚥ K(5),C1 +2 +(2), A(9) +1, G1
Features of the Liliaceae family
Allium cepa
Floral Features
Umbellate clusters and solitary Cymose inflorescences are typical of the Liliaceae family.
The members of the Liliaceae family have six white-coloured tepals (indistinctive sepal and petal), which form the perianth and show valvate aestivation. The tepals are arranged in two whorls.
In the Liliaceae family, the androecium has six stamens arranged in two whorls, dorsifixed, introse, epiphyllous and polyandrous.
The gynoecium of the Liliaceae family is tricarpellary, superior ovary, syncarpous, trilocular, and axile placentation.
Floral formula: ⊕⚥P3+3A3+3G(3) or P(3+3)
Results
Petunia nyctanginifolia belongs to the Solanaceae family as it contains violet colour flowers in an infundibuliform shape, having a capitate stigma, and the ovary shows axile placentation.
Pisum sativum belongs to the Fabaceae family as the flowers show papilionaceous corolla containing 3 types of petal- 1 standard, 2 wings and 2 keels and the androecium contains a 10+2 arrangement of stamens.
Allium cepa belongs to the family Liliaceae because the perianth is gamophyllous, gynoecium is tricarpellary, syncarpous and with axile placentation and stamens are epiphyllous.
Precautions
Be careful while dissecting delicate parts of the flower.
Take thin sections of the specimens for clear vision under the microscope.
Lab Manual Questions
1. Which placentation would result in an ovary that is always unilocular?
Ans: The ovary in basal placentation is unilocular. At the base of the ovary, it has a single placenta with a single ovule attached to it.
2. What are the floral components' positions if a flower is epigynous?
Ans: A form of flower known as an epigynous flower has floral portions above the ovary and an ovary in the deep part of the flower. When the floral components are attached near the top of the ovary, it is referred to as an inferior ovary or epigynous flower.
3. What is a zygomorphic flower?
Ans: Flowers, when dissected through a particular plane, can be equally divided into two halves known as zygomorphic flowers. These are bilaterally symmetrical flowers. E.g. Pea, Orchids, Snapdragon etc.
4. How do you identify a family of Liliaceae?
Ans: Flowers have separate but undifferentiated sepals and petals that can be spotted or striped, and they are radially symmetrical, with parts appearing in groups of three. A capsule makes up the fruit.
Viva Questions
1. Describe a flower
Ans: A flower is a part of a plant with distinct colours and forms. It is a reproductive part of a plant.
2. How many whorls does a flower typically have?
Ans: A flower typically has four whorls.
3. Identify the essential flower whorls.
Ans: Gynoecium and Androecium are the names of essential whorls.
4. What type of flower is produced by Allium?
Ans: The flowers are hermaphrodite, actinomorphic, complete, pedicellate, bracteate, and white.
5. Which family is commonly referred to as the potato family?
Ans: Solanaceae family is commonly referred to as the potato family.
6. Mention the petunia's inflorescence.
Ans: Cymose inflorescence
7. What defines the pea flower?
Ans: The pea flower contains one standard, two wings, and two keels (united ) type of corolla since the pea belongs to the fabaceae family. This characteristic separates members of the fabaceae family from the others.
8. Give the names of the four floral whorls.
Ans: A flower has four whorls, which are: Corolla, Calyx, Androecium, and Gynoecium.
9. Name one dicotyledonous flower
Ans: Roses are the best example of a dicot flower.
10. Name two plants that are analogous to petunia.
Ans: The following two plants resemble petunias:
Solanum tuberosum (potato) and S. melongena (brinjal)
Practical Based Questions
Ovules on sutures and a syncarpous, unilocular ovary are characteristics of which type of placentation.
A) Parietal placentation
B) Marginal placentation
C) Apical placentation
D) Superficial placentation
Ans: Apical placentation
When the petal and sepal edges do not cross one another in any direction, the situation is referred to as
A) Vexillary
B) Valvate
C) Imbricate
D) Twisted
Ans: Valvate
The term for flowers that have both androecium and gynoecium is
A) Bisexual flowers
B) Stamen
C) Anther
D) Unisexual flower
Ans: Bisexual flower
Which of the following components of a flower are not necessary
A) Androecium and gynoecium
B) Sepals and Carpels
C) Sepals and petals
D) Sepals and gynoecium
Ans: Sepals and petals
Androecium consists of a
A) Style
B) Stigma
C) Stamens
D) None of the above
Ans: Stamens
Two or more syncarpous gynoecium are present
A) Free ovaries
B) Free carpels
C) Fused carpels
D) All of the above
Ans: Fused carpels
The following is the name of a typical lower with a superior ovary and inferior floral parts
A) Perigynous
B) Epigynous
C) Polygamous
D) Hypogynous
Ans: Hypogynous
Type of flowers with just one of the essential whorls
Unisexual
Bisexual
Polygamous
None of the above
Ans: Unisexual
In which plant family infundibuliform corolla is present
A) Fabaceae
B) Solanaceae
C) Liliaceae
D) Rosaceae
Ans: Solanaceae
Which family shows marginal placentation?
A) Rosaceae
B) Liliaceae
C) Solanaceae
D) Fabaceae
Ans: Fabaceae
Summary
Plant taxonomists believe that there are around 4 million different plant species worldwide. Angiosperms (flowering plants) make up around two-three lakh of these species, along with gymnosperms, bryophytes, and other vascular and nonvascular plants. Based on their traits, these plants are divided into many families. Common characteristics that the Solanaceae and Fabaceae families exhibit are alternate leaves, compound leaves, perfect flowers, etc.
FAQs on To Study And Describe Flowering Plants Of Families- Solanaceae, Fabaceae And Liliaceae
1. What are the most frequently asked topics from the plant families Solanaceae, Fabaceae, and Liliaceae in the Class 11 Biology exam?
For the CBSE Class 11 exams (2025-26 session), the most important topics from these families are:
- Writing the correct floral formula and drawing the floral diagram for each family.
- Identifying the key diagnostic features that distinguish one family from another.
- Providing examples of economically important plants for each family (e.g., pulses from Fabaceae, vegetables from Solanaceae, ornamentals from Liliaceae).
- Understanding the specific types of inflorescence, aestivation, and placentation in each family.
2. How can I score full marks on a 3-mark question about the floral characteristics of the Solanaceae family?
To secure full marks, you should describe the key floral features clearly. A good answer would mention that the flower is actinomorphic and bisexual. Describe the calyx as having five fused sepals (gamosepalous) and the corolla as having five fused petals (gamopetalous). Crucially, mention that the five stamens are epipetalous (attached to the petals) and the gynoecium is bicarpellary, syncarpous, with a superior ovary that is characteristically obliquely placed.
3. What are the key diagnostic features to identify a plant from the Fabaceae family for an exam?
For exam identification, focus on these unique features of the Fabaceae family:
- Corolla: It shows vexillary aestivation, consisting of one large standard petal, two lateral wings, and two fused anterior petals forming a keel.
- Androecium: The stamens are typically diadelphous, meaning they are arranged in two bundles, usually (9)+1.
- Gynoecium: It has a monocarpellary, superior ovary with marginal placentation.
- Fruit: The fruit is typically a legume or pod.
4. How do I correctly write the floral formula for a plant from the Liliaceae family?
The floral formula for the Liliaceae family summarises its key features. It is written as: Br. ⊕ ⚥ P(3+3) A3+3 G(3). Here’s what each symbol means:
- Br: Bracteate (the flower has a bract).
- ⊕: Actinomorphic (radially symmetrical).
- ⚥: Bisexual (has both male and female parts).
- P(3+3): Perianth with six tepals arranged in two whorls of three, which are fused.
- A3+3: Androecium with six stamens in two whorls of three.
- G(3): Gynoecium with three fused carpels (syncarpous) and a superior ovary.
5. Why is the Fabaceae family considered economically important? What examples are relevant for exams?
The Fabaceae family is highly significant economically, a point often tested in exams. This is because it is a major source of food and other products. For your exam, remember these examples:
- Pulses: Gram (chana), arhar, moong, and peas are staple food sources rich in protein.
- Edible Oils: Soybean and groundnut are major sources of cooking oil.
- Fodder: Plants like Sesbania and Trifolium are used as animal feed.
- Fibres: Sunn hemp provides strong fibres.
- Medicinal Plants: Muliathi has medicinal properties.
6. What is a key difference between the gynoecium of Solanaceae and Liliaceae that is important for exams?
The most important difference lies in the number of carpels. The gynoecium in the Solanaceae family is bicarpellary, meaning it is composed of two carpels. In contrast, the gynoecium in the Liliaceae family is tricarpellary, composed of three carpels. Both are syncarpous (fused) with a superior ovary and axile placentation, but the number of carpels is a critical distinction.
7. What are some common mistakes students make when drawing the floral diagram for the Solanaceae family?
Students often lose marks on floral diagrams due to small errors. For Solanaceae, watch out for these common mistakes:
- Forgetting to show the fusion of sepals and petals using connecting lines.
- Not drawing the stamens as epipetalous, which means they must be shown attached to the petals.
- Incorrectly drawing the ovary. It must be shown as bicarpellary (two locules) and, most importantly, drawn obliquely, not straight.
- Placing the mother axis in the wrong position (it should be posterior).
8. How does placentation help in distinguishing these three families?
Placentation is a very useful feature for distinguishing these families. The Fabaceae family is characterised by marginal placentation in a single carpel. Both Solanaceae and Liliaceae exhibit axile placentation, where ovules are attached to a central axis. However, you can tell them apart because in Solanaceae the ovary is bicarpellary (two-chambered), while in Liliaceae it is tricarpellary (three-chambered).
