RBSE Solutions Class 11 Biology Chapter 25 Families of Angiosperms

Rajasthan Board RBSE Class 11 Biology Chapter 25 Families of Angiosperms

RBSE Class 11 Biology Chapter 25 Multiple Choice Objective Questions

 

Question 1. Which character is same in Malvaceae, Solanaceae and Liliaceae?
(a) Axile placentation
(b) Numbers of stamens
(c) Presence of epicalyx
(d) Presence of stamina tube
Answer: (a) Axile placentation
In simple words: All three plant families – Malvaceae, Solanaceae, and Liliaceae – share a common feature where the ovules grow from the central axis of the ovary. This type of ovule arrangement is called axile placentation.

🎯 Exam Tip: Understanding different types of placentation (like axile, parietal, free central, basal) is crucial for classifying plant families. Memorize key examples for each type.

 

Question 2. Which plant is named as fire of forest or dhak or tesu or palash?
(a) Coronopus
(b) Cassia
(c) Butea
(d) Thespesia
Answer: (c) Butea
In simple words: The plant Butea, also known as Palash, is famously called the "fire of the forest" because its bright orange-red flowers bloom in summer, making the trees look like they are on fire. This beautiful display happens when the trees have no leaves, making the flowers stand out even more.

🎯 Exam Tip: Knowing common names of important plants, especially those with cultural or ecological significance, is often tested. Associate common names with their scientific botanical names.

 

Question 4. Trimerous epicalyx is characteristic of which family?
(a) Malvaceae
(b) Solanaceae
(c) Fabaceae
(d) Liliaceae
Answer: (d) Liliaceae
In simple words: A trimerous epicalyx, meaning an extra set of leaf-like structures below the sepals in groups of three, is a special feature seen in the Liliaceae family. This distinct structure helps identify plants belonging to this family.

🎯 Exam Tip: Floral characteristics like the number of parts (dimerous, trimerous, pentamerous) and the presence of accessory whorls (like epicalyx) are crucial for identifying specific plant families.

 

Question 5. Mimosa pudica is commonly known as:
(a) Touch me not
(b) Candytuft
(c) Khejari
(d) Gulmohar
Answer: (a) Touch me not
In simple words: Mimosa pudica is widely known by its common name, the "touch-me-not" plant. It gets this name because its leaves quickly fold inward and droop when touched, a remarkable protective mechanism.

🎯 Exam Tip: Familiarize yourself with common names of plants that have unique characteristics or are often featured in textbooks, as these are easy questions to score on.

RBSE Class 11 Biology Chapter 25 Very Short Answer Questions

 

Question 1. What do you mean by epicalyx?
Answer: An epicalyx is an additional whorl of bracteoles located below the calyx of a flower. The number of bracteoles can vary from three to many, forming this distinct ring-like structure. This extra protective layer helps shield the developing flower parts.
In simple words: Epicalyx is like an extra set of small leaves right below the main outer part of a flower (the calyx).

🎯 Exam Tip: Clearly define accessory floral whorls like epicalyx and involucel, and mention their position relative to the main calyx.

 

Question 2. What do you mean Tetradynamous stamens?
Answer: Tetradynamous stamens refer to a specific arrangement of stamens found in flowers, most notably in the mustard family (Brassicaceae). In this arrangement, there are six stamens in total: four of them are long, and two are shorter. This unique setup is a characteristic feature that helps identify these plants.
In simple words: Tetradynamous stamens mean a flower has six stamens, with four long ones and two short ones.

🎯 Exam Tip: Be precise when describing stamen arrangements (e.g., didynamous, tetradynamous) as these are key diagnostic features for many plant families.

 

Question 3. Draw the labelled of the show cross form petals in Cruciferae.
Answer:

The diagram above is a simplified representation of the floral diagram of Cruciferae, showing the arrangement of sepals (K), petals (C), stamens (A), and gynoecium (G) in concentric whorls. The cross-shaped arrangement of petals is a defining feature. The actual detailed botanical illustrations (flowering twig, L.S. of flower, T.S. of ovary, etc.) are complex and not suitable for a simple SVG representation.
In simple words: The flower diagram for Cruciferae shows petals arranged like a cross. This is a special way the flower parts are laid out.

🎯 Exam Tip: When drawing floral diagrams, clearly label each whorl (calyx, corolla, androecium, gynoecium) and indicate the number of parts, their fusion (if any), and aestivation.

 

Question 4. Explain monoadelphous and didelphous condition.
Answer: In a monoadelphous condition, all the filaments (stalks) of the stamens in a flower are fused together to form a single bundle or tube. This means they are united into one group. On the other hand, in a didelphous condition, the filaments of the stamens are fused into two separate bundles. This creates two distinct groups of stamens within the flower.
In simple words: Monoadelphous means all stamen stalks are joined into one group, while didelphous means they are joined into two separate groups.

🎯 Exam Tip: Distinguish clearly between adelphous conditions (mono-, di-, poly-) based on the number of stamen bundles formed by filament fusion. Provide examples if possible.

 

Question 5. Write floral formula of Solanaceae.
Answer: The floral formula for the Solanaceae family is typically represented as:
\( \text{Br. Or Ebr } \text{♀} \oplus \text{K}_{(5)} \text{ C}_{(5)} \text{ A}_5 \text{ G}_{\underline{(2)}} \)
This formula indicates that the flowers can be bracteate or ebracteate, are bisexual, actinomorphic (radially symmetrical), have five fused sepals, five fused petals, five free stamens attached to the petals, and a superior ovary with two fused carpels. Understanding this formula helps in identifying the unique features of the family.
In simple words: The floral formula for Solanaceae shows that flowers are regular, bisexual, have five fused sepals, five fused petals, five stamens attached to petals, and a two-chambered superior ovary.

🎯 Exam Tip: Memorize the standard symbols used in floral formulas and practice writing them for common families, paying attention to fusion, adhesion, and ovary position.

 

Question 6. Write the botanical name the plant 'Mulhati' used in coughing.
Answer: The botanical name for the plant 'Mulhati', which is commonly used to treat coughing, is Glycyrrhiza glabra. This plant is well-known for its sweet roots and medicinal properties. It is often found in traditional remedies for respiratory issues due to its soothing effects.
In simple words: The plant 'Mulhati', used for coughs, is scientifically called Glycyrrhiza glabra.

🎯 Exam Tip: When asked for botanical names, ensure correct spelling and formatting (Genus capitalized, species lowercase, both italicized).

 

Question 7. What do you mean by persistent calyx?
Answer: A persistent calyx refers to the sepals (the outermost whorl of a flower) that remain attached to the fruit even after fertilization and fruit development. Unlike many flowers where sepals wither and fall off, in some plants, they continue to grow or remain present, sometimes even enclosing the fruit. This characteristic is visible in fruits like tomatoes and brinjal (eggplant).
In simple words: Persistent calyx means the sepals stay on the fruit even after the flower has turned into a fruit.

🎯 Exam Tip: Provide clear examples of plants with persistent calyx (e.g., brinjal, tomato, Physalis) to illustrate the concept effectively.

 

Question 8. Name the disease for which roots of Ashwagandha is used.
Answer: The roots of Ashwagandha are used in traditional medicine to treat several ailments, including hiccup, cough, and rheumatism. A drug known as asgandh is extracted from these roots. This medicinal plant is highly valued for its therapeutic properties.
In simple words: Ashwagandha roots are used to treat hiccups, coughs, and rheumatism.

🎯 Exam Tip: Focus on recalling specific uses or medicinal properties of common plants mentioned in your syllabus for such direct questions.

 

Question 9. Which plant of Liliaceae is used as raticide?
Answer: Urginea indica, a plant belonging to the Liliaceae family, is used as a raticide. The powder derived from its bulbs is effective in killing rats. This traditional use highlights the toxic properties of certain plants within this family.
In simple words: The plant Urginea indica from the Liliaceae family has bulbs that are powdered and used to kill rats.

🎯 Exam Tip: Remember specific examples of plants and their unique economic or ecological uses, especially when they differ from the typical characteristics of their family.

 

Question 10. Why Khejari is called as tree of heaven?
Answer: Khejari (Prosopis cineraria) is often called the "tree of heaven" because every part of the plant is incredibly useful to the local people of Rajasthan. Its leaves serve as fodder, pods are eaten, wood is used for timber and fuel, and it helps in soil conservation. This tree provides vital resources in arid regions, making it invaluable to the community.
In simple words: Khejari is called the "tree of heaven" because all its parts, like leaves, pods, and wood, are very useful to people, especially in Rajasthan.

🎯 Exam Tip: When explaining cultural or common names of plants, provide concrete reasons or uses that justify the name.

RBSE Class 11 Biology Chapter 25 Short Answer Questions

 

Question 1. What do you mean by Papilineocious corolla?
Answer: A Papilionaceous corolla is a specific type of butterfly-shaped corolla found in flowers of the pea family (Fabaceae, subfamily Papilionaceae). It consists of five distinct petals arranged in a characteristic pattern: one large, outermost standard petal (vexillum), two lateral wing petals (alae), and two inner, often fused, keel petals (carina) that enclose the stamens and pistil. This unique shape helps in insect pollination.
In simple words: A Papilionaceous corolla is a special butterfly-shaped flower made of five petals: a large one on top, two on the sides, and two joined together at the bottom.

🎯 Exam Tip: When defining specific floral terms, clearly describe the structure, number of parts, and their arrangement, and mention the family where it is common.

 

Question 2. What were the bases to divide family Leguminosae in to subfamilies?
Answer: The family Leguminosae (now commonly known as Fabaceae) was divided into three sub-families primarily based on the distinct characteristics of their corolla, specifically its aestivation (arrangement of petals in the bud), androecium (stamens), and other floral traits. These differences in flower structure are key to distinguishing between Papilionaceae, Caesalpinioideae, and Mimosoideae.
In simple words: The Leguminosae family was split into sub-families mainly based on how their flower petals were arranged and the features of their stamens.

🎯 Exam Tip: Focus on major floral characteristics (like aestivation, stamen arrangement, symmetry) as key criteria for classification within large plant families.

 

Question 3. Write distinguish characters of Mimosoideae.
Answer: The distinguishing characters of Mimosoideae, a subfamily of Fabaceae, include actinomorphic (radially symmetrical) flowers, valvate aestivation where petals meet without overlapping in the bud, and an indefinite number of stamens that are typically free (not fused). These features help differentiate Mimosoideae from other subfamilies.
In simple words: Mimosoideae flowers are round and symmetrical, their petals meet without overlapping, and they have many stamens that are not joined together.

🎯 Exam Tip: When listing distinguishing characters, ensure you cover key floral features such as symmetry, aestivation, and stamen arrangement and number.

 

Question 4. Write the floral formula of a flower having actinomorphic symmetry, bisexual, hypogynous, 5 gamoseplous, 5 polypetaous, 5 polyandrous, bicarpellary and superior ovary.
Answer: The floral formula for a flower with the given characteristics would be:
\( \oplus \text{♀} \text{ K}_{(5)} \text{ C}_5 \text{ A}_5 \text{ G}_{\underline{(2)}} \)
This formula represents a flower that is actinomorphic (radially symmetrical) and bisexual. It has 5 fused sepals (gamosepalous), 5 free petals (polypetalous), 5 free stamens (polyandrous), and a superior ovary composed of two fused carpels (bicarpellary, syncarpous). This concise formula provides a snapshot of the flower's structure.
In simple words: The floral formula describes a regular, bisexual flower with 5 joined sepals, 5 separate petals, 5 separate stamens, and a superior ovary made of two joined parts.

🎯 Exam Tip: Practice converting descriptive floral characteristics into their standard floral formula notation, paying close attention to fusion, adhesion, and ovary position symbols.

 

Question 5. How can you separate the ovaries of Leguminosae from Liliaceae? Write the identification characters.
Answer: The ovaries of Leguminosae and Liliaceae can be separated by their distinct identification characters. In Leguminosae, the ovary is typically monocarpellary, meaning it consists of a single carpel, and exhibits marginal placentation, where the ovules are arranged along the fused margin of the carpel. In contrast, the Liliaceae family features a tricarpellary ovary, meaning it is made of three fused carpels, with axile placentation, where ovules are attached to a central axis formed by the fusion of carpel walls.
In simple words: Leguminosae ovaries have one carpel with seeds along the edge, while Liliaceae ovaries have three joined carpels with seeds along a central stalk.

🎯 Exam Tip: Focus on key distinguishing features like the number of carpels, fusion (apocarpous/syncarpous), and placentation type for differentiating ovaries of different plant families.

 

Question 6. Write the characteristics of androecium from Malvaceae family.
Answer: The androecium (male reproductive part) in the Malvaceae family has several distinctive characteristics. It consists of an indefinite number of stamens which are monadelphous, meaning their filaments are united to form a long staminal tube or column. This column encloses the style. The basal part of this staminal tube is often fused with the petals, making the stamens epipetalous. Furthermore, the anthers are monothecous (having a single lobe), reniform (kidney-shaped), dorsifixed (attached by their back), and extrorse (dehiscing outwards).
In simple words: In Malvaceae, there are many stamens, and their stalks are joined into a tube around the style. The anthers have one lobe, are kidney-shaped, attached from the back, and open outwards.

🎯 Exam Tip: When describing androecium, include details about the number of stamens, their fusion (adelphy), attachment to other floral parts (epipetalous), anther structure (mono/dithecous), and dehiscence (introrse/extrorse).

 

Question 8. Write the botanical name of two plants and two distinguish characters from Cruciferae family.
Answer: Two botanical names of plants from the Cruciferae family (Brassicaceae) are:
1. Brassica oleracea var botrytis (Cauliflower)
2. Brassica oleracea var capitata (Cabbage)

Two distinguishing characters of the Cruciferae family are:
1. The presence of sulphur-containing mercaptan compounds, which give a pungent smell.
2. Flowers typically have a cruciform corolla (petals arranged in a cross shape) and tetradynamous stamens (four long and two short stamens).
In simple words: Two plants are Cauliflower and Cabbage. Two key features of this family are their strong smell due to special compounds and their cross-shaped flowers with six stamens of different lengths.

🎯 Exam Tip: For family descriptions, always list specific examples of plants along with their botanical names, and clearly state 2-3 unique distinguishing floral or vegetative features.

 

Question 9. Write the name of family on the basis of following characters:
a. Zygomorphic, didelphous and marginal placentation in a flower.
b. Epicalyx present, stamens are infinite, monoadelphous and axile placentation.
c. Cruciform corolla, stamen's are tetradynamous and parietal placentation.
Answer:
(a) Papilionaceae
(b) Malvaceae
(c) Brassicaceae
In simple words: Based on the given flower features, (a) belongs to the Papilionaceae family, (b) belongs to the Malvaceae family, and (c) belongs to the Brassicaceae family. Each family has its own unique set of characteristics.

🎯 Exam Tip: Practice identifying plant families based on a combination of floral characteristics like symmetry, stamen arrangement, placentation, and corolla type.

RBSE Class 11 Biology Chapter 25 Essay Type Questions

 

Question 1. Explain in detail Cruciferae family with its floral characters. Draw floral diagram and write floral formula.
Answer: The Cruciferae family, also known as Brassicaceae (Mustard family), is a large and economically important plant family. It includes many familiar plants like mustard, cabbage, radish, and cauliflower.

Floral Characters:
1. Inflorescence:

• The inflorescence is typically racemose, meaning flowers grow along a central axis, with older flowers at the base and younger ones at the apex. A common example is the raceme found in mustard. Some species, like Candytuft, may show a corymb inflorescence.

2. Flower:

• Flowers are ebracteate (lacking bracts), pedicellate (having stalks), complete (all four whorls present), and bisexual. They are usually actinomorphic (radially symmetrical), but in some cases like Candytuft (Iberis amara), they can be zygomorphic (bilaterally symmetrical).

3. Calyx:

• The calyx consists of 4 sepals, arranged in two whorls of two each. They are polysepalous (free sepals). The aestivation is valvate or imbricate.

4. Corolla:

• The corolla has 4 petals, which are polypetalous (free). They are arranged diagonally in a cross-like (cruciform) manner, which gives the family its name. Each petal is differentiated into a lower, narrow claw and an upper, broader limb. Aestivation is valvate.
• In some plants like Coronopus, petals may be absent. In Candytuft, two anterior petals are often larger than the two posterior ones, contributing to zygomorphy.

5. Androecium:

• The androecium typically consists of 6 stamens, arranged in a tetradynamous pattern (2 short outer stamens and 4 long inner stamens). They are polyandrous (free). The anthers are bithecous (two-lobed), basifixed (attached at the base), and introrse (opening inwards). Sometimes, nectariferous glands are present at the base of the stamens.

6. Gynoecium:

• The gynoecium is bicarpellary (two carpels), syncarpous (fused carpels), forming a superior, unilocular (single-chambered) ovary. Initially unilocular, it becomes bilocular due to the formation of a false septum called replum. Placentation is parietal, with ovules arranged on the inner walls of the ovary. The style is simple, and the stigma is usually bilobed.

7. Floral formula:
The floral formula for Cruciferae is:
\( \text{Ebr } \text{♀} \oplus \text{K}_{2+2} \text{ C}_4 \text{ A}_{2+4} \text{ G}_{\underline{(2)}} \)

8. Fruit:

• Fruits are typically siliqua (long, dehiscent capsule) or silicula (short, dehiscent capsule). Examples include Capsella, Iberis, and Alyssum which have silicula fruits.

9. Seed:

• Seeds are exalbuminous or non-endospermic, meaning they do not contain endosperm tissue.

The diagram above is a simplified representation of the floral diagram of Cruciferae, showing the arrangement of sepals (K), petals (C), stamens (A), and gynoecium (G) in concentric whorls. The cross-shaped arrangement of petals is a defining feature.
In simple words: The Cruciferae family (like mustard plants) has flowers with four petals arranged like a cross, six stamens (four long, two short), and a two-chambered ovary. The floral formula uses symbols to quickly show these features.

🎯 Exam Tip: For detailed family descriptions, ensure you cover vegetative and floral characters comprehensively. Always include the floral formula and a representative floral diagram for full marks.

 

Question 2. Write economic importance of family Malvaceae.
Answer: The Malvaceae family is economically important for several reasons. Many plants from this family provide fibers, such as cotton (Gossypium spp.), which is a major source of textile fibers worldwide. Other plants yield edible fruits like okra (Abelmoschus esculentus) or medicinal compounds. Additionally, some members are grown as ornamental plants for their beautiful flowers, like Hibiscus.

Distinguish characters of Malvaceae:

• Mostly, an epicalyx (an extra whorl of bracteoles below the calyx) is present.
• The aestivation of the corolla (petal arrangement in the bud) is typically twisted.
• Stamens are indefinite in number and are monoadelphous, meaning their filaments fuse to form a staminal tube.
• Anther lobes are monothecous (single-lobed), reniform (kidney-shaped), and extrorse (opening outwards).
• Stigmas are numerous, matching the number of carpels.
• Axile placentation is observed, where ovules are attached to the central axis of the ovary.
• Mucilage-secreting glands are commonly present in the plants.
• Stellate hairs (star-shaped hairs) are found on the vegetative parts of the plants.

In simple words: Malvaceae plants are important for cotton fiber, food like okra, and beautiful flowers. Key features include an extra layer below the flower (epicalyx), twisted petals, many stamens joined in a tube, and a special type of ovule attachment called axile placentation.

🎯 Exam Tip: When describing economic importance, categorize the uses (fiber, food, medicinal, ornamental). For distinguishing characters, list 5-7 clear and concise points covering floral and vegetative traits.

 

Question 3. Do comparative study of all three subfamilies of Leguminosae and write the name of three economically important plants with its botanical name from each.
Answer: The Leguminosae family (now Fabaceae) is divided into three subfamilies: Papilionaceae, Caesalpinioideae, and Mimosoideae, each with distinct characteristics and economic importance.

Sub-family Papilionaceae:

• Classification: Class - Dicotyledones, Sub-class - Polypetalae, Series - Calyciflorae, Order - Rosales, Family - Leguminosae.
• These are mostly herbs, climbers, twiners, shrubs, or trees found in tropical and subtropical areas.
• In India, this subfamily is represented by about 100 genera and 750 species.

Economically Important Plants (Papilionaceae):
1. Arachis hypogaea (Peanut)
2. Pisum sativum (Garden pea)
3. Glycine max (Soyabean)

Vegetative Characters of Papilionaceae:
1. Habit:

• Mostly herbs (e.g., Melilotus, Cajanus cajan, Medicago, Trigonella).
• Climbers (e.g., Lathyrus, Pisum) and twiners (e.g., Dolichos, Phaseolus) are common.
• Some are shrubs (e.g., Cajanus cajan, Crotalaria juncea, Butea) or trees (e.g., Dalbergia, Erythrina).
• Xerophytes like Alhagi also exist.

2. Roots:

• Tap roots are present and have nodules that contain nitrogen-fixing Rhizobium bacteria. These bacteria form a symbiotic association, converting atmospheric nitrogen into nitrites or nitrates, thereby increasing soil fertility. These are also known as nodulated roots.

3. Stem:

• Stems can be herbaceous or woody, sometimes weak (tendril or leaf climbers). They are erect, creeping, branched, cylindrical, and angular.

4. Leaves:

• Leaves are alternate and stipulate.
• The leaf base is swollen, forming a pulvinus.
• Venation is reticulate.
• Stipules can be adnate (fused to petiole) as in Medicago and Trifolium.
• Leaves are simple (e.g., Alysicarpus), palmately compound (e.g., Melilotus, Trifolium), or pinnately compound (e.g., Sesbania, Dalbergia, Lathyrus).

Floral Characters of Papilionaceae:
1. Inflorescence:

• Typically racemose type. Examples include racemes in Pisum and Melilotus alba, spikes in Uraria, axillary heads in Trifolium, solitary axillary flowers in Lathyrus, racemose cymes in Tephrosia, and panicled racemes in Dalbergia.

2. Flowers:

• Flowers are bracteate or bracteolate, pedicellate, complete, cyclic, bisexual, and pentamerous. They are notably zygomorphic (bilaterally symmetrical) and usually hypogynous or slightly perigynous.

3. Calyx:

• Consists of 5 united sepals (gamosepalous). The odd sepal is anterior. Aestivation is valvate or imbricate.

4. Corolla:

• Composed of 5 petals, which are polypetalous and characteristically papilionaceous. Aestivation is vexillary or descending imbricate.
• The largest posterior petal is the standard (vexillum). Two lateral petals are called wings, and two anterior petals, often fused to form a boat-shaped structure, are called the keel (carina).
• In Lespedeza, the corolla may be absent.

5. Androecium:

• Typically 10 stamens, usually diadelphous (9 fused and 1 free) or sometimes monadelphous (all 10 fused) as in Pongamia. Rarely, they are polyandrous (free) as in Sophora.
• Anthers are dithecous (two-lobed), dorsifixed (attached by their back), and introrse (opening inwards).

6. Gynoecium:

• Monocarpellary (single carpel) with a superior, unilocular ovary. It has many ovules on ventral sutures. In Lespedeza, the ovary has only a single ovule.
• Placentation is marginal. The style is simple, single, and long, and the stigma is often capitate or sword-shaped (in Pisum).

7. Floral Formula:
\( \text{Br. Or Brl } \text{♀} \% \text{ K}_{(5)} \text{ C}_{1+(2)+(2)} \text{ A}_{1+(9)} \text{ G}_{\underline{1}} \)

8. Fruit:

• Fruits are legumes (pods). In Arachis hypogaea (groundnut), the lomentum is geocarpic (develops underground). In Dalbergia, the fruit is indehiscent and winged.

9. Seed:

• Seeds are exalbuminous or non-endospermic.

**Subfamily Caesalpinioideae:** (Content not provided in OCR for this section, so I cannot process it.)

**Subfamily Mimosoideae:** (Content not provided in OCR for this section, so I cannot process it.)

In simple words: The Leguminosae family has three subfamilies. Papilionaceae, for example, includes peanuts and peas. They have special roots that fix nitrogen, and their flowers are often butterfly-shaped with stamens grouped together.

🎯 Exam Tip: For comparative studies, create a table highlighting key differences in vegetative and floral characters (e.g., symmetry, aestivation, stamen arrangement, placentation) for each subfamily, and list their important plant examples.

 

Question 10. Distinguish characters of Papilionaceae

• Flower is zygomorphic (bilaterally symmetrical).
• Aestivation (petal arrangement) is descending imbricate or vexillary.
• Corolla is Papilionaceous (butterfly-shaped).
• Stamens are diadelphous (9 fused, 1 free).
• Root nodules with Rhizobium bacteria are present in roots for nitrogen fixation.

Answer: (The distinguishing characters are already listed in the question for this specific format. The question itself is a request for these distinguishing characteristics). These features collectively make the Papilionaceae subfamily distinct. They are crucial for identification and classification within the larger Fabaceae family.
In simple words: Papilionaceae flowers have a special butterfly shape, their petals overlap in a specific way, their stamens are in two groups, and their roots have bumps with bacteria that help the soil.

🎯 Exam Tip: When a question asks for distinguishing characters, ensure you list unique features that are not common to other closely related groups, covering both floral and vegetative aspects.

 

Question 4. Explain vegetative characters of family Solanceae. Write its economic importance also.
Answer: The Solanaceae family, commonly known as the Nightshade family, includes many economically important plants, such as potato, tomato, brinjal, chili, and tobacco.

Vegetative Characters:
1. Habit:

• Most plants in this family are herbs or shrubs, with only a few being small trees.
• Examples of annual herbs include Nicotiana (tobacco).
• Perennial herbs include Withania somnifera (Ashwagandha).
• Shrubs like Cestrum (Night blooming Jasmine) and Solanum dulcamara are also common.
• Solanum verbscifolium is an example of a small tree.

2. Root:

• Plants typically possess a tap root system.

3. Stem:

• The stem is usually erect, solid, cylindrical, and branched.
• Occasionally, it can be spinous, as seen in Solanum xanthocarpum.
• In potato (Solanum tuberosum), the underground stem is modified into tubers, which are used for food storage.

4. Leaf:

• Leaves are alternate, exstipulate (without stipules), and simple, with either entire or lobed margins.
• Venation is cauline and unicostate reticulate, meaning veins form a net-like pattern.
• The leaf surface can be hairy.
• In some plants like tomato (Lycopersicon) and potato, the leaves are pinnately compound.

Economic Importance:
The Solanaceae family is of immense economic importance globally:
1. Food: It provides major food crops such as potato (Solanum tuberosum), tomato (Lycopersicon esculentum), brinjal (Solanum melongena), and chili (Capsicum annuum).
2. Spices: Chili is widely used as a spice.
3. Medicinal Plants: Ashwagandha (Withania somnifera) is used in traditional medicine for various ailments. Belladonna (Atropa belladonna) is another source of medicinal compounds.
4. Tobacco: Nicotiana tabacum is the source of tobacco.
5. Ornamental Plants: Petunia and ornamental varieties of Datura are grown for their attractive flowers.
In simple words: Solanaceae plants are usually herbs or shrubs with taproots, branched stems, and simple leaves. They are very important for food (like potatoes and tomatoes), spices (chili), medicines (Ashwagandha), and tobacco.

🎯 Exam Tip: When describing vegetative characters, cover habit, root type, stem features (including modifications), and leaf characteristics (phyllotaxy, venation, stipules). For economic importance, list specific plants and their uses under clear categories.

 

Question 6. Explain in detail Liliaceae family with its floral characters. Draw floral diagram and write floral formula. Write the botanical name of 5 economically important plants from this family.
Answer:

Floral Characters:

1. Inflorescence:

• The Liliaceae family has different types of flower arrangements.
• Racemose: In plants like Yucca and Asphodelus, flowers grow in a raceme. In Aloe, they form a spike, and in Smilax, they appear in an umbel.
• Cymose: For plants like Tulipa, Lilium, and Paris, flowers are solitary and grow at the tip. Gloriosa has solitary flowers in the leaf axils. Hemerocallis has flowers in scorpioid cymes. In Allium, the flower cluster looks like an umbel because the stem between nodes is very short.

2. Perianth:

• The flowers have bracts (small leaf-like structures) or no bracts. They are on stalks, complete, meaning they have all parts, and are bisexual (have both male and female parts).
• They are actinomorphic (can be divided into two equal halves from any plane) and trimerous (parts in multiples of three). The ovary is hypogynous (positioned above other floral parts).
• Sometimes, the flowers can be zygomorphic (can be divided into two equal halves from only one plane), like in Haworthia and Gillesia.
• Some flowers are unisexual and trimerous, as seen in Smilax and Ruscus.
• In Paris and Aspidiastra, flowers have parts in multiples of four (tetramerous) and are actinomorphic, but in Aloe and Lilium, they are zygomorphic.

3. Androecium:

• There are usually six stamens. They are arranged in two groups of three (3+3).
• The stamens are polyandrous, meaning they are free.
• The filament (stalk of the stamen) can be joined to the tepals (epiphyllous), like in Allium and Asphodelus, or they can be free and opposite the tepals, like in Smilax.
• In tetramerous flowers, there are eight stamens arranged in two whorls of four each (4+4).
• In Ruscus, the three stamens are fused together.
• The anthers have two lobes (dithecous), are attached at their base (basifixed) or back (dorsifixed), and open inwards (introrse).
• Sometimes, the stamens in the outer whorl are smaller or do not produce pollen (sterile), as in Ruscus.

4. Gynoecium:

• The female part, the gynoecium, has three fused carpels (tricarpellary, syncarpous). The ovary is superior (above other floral parts) and has three compartments (trilocular). It contains many ovules in each compartment, arranged on the central axis (axile placentation).
• The style (stalk connecting the stigma and ovary) is simple, and the stigma (pollen-receiving part) has three lobes.
• Often, a small nectar-producing gland is present on each wall of the ovary compartment.

6. Pollination:

• Pollination in this family is usually carried out by insects (entomophilous).
• In potato (Solanum tuberosum), self-pollination happens.

7. Floral Formula:
Br. Or Ebr. \( \text{ ⚥ } \) \( \text{ * } \) \( \text{ P}_{ (3+3) } \) \( \text{ A}_{ (3+3) } \) \( \underline{ \text{ G } }_{ (3) } \)

8. Fruit:

• The fruit is typically a simple, dry capsule.
• It can be loculicidal (splitting along the middle of the compartments) in Asphodelus or septicidal (splitting along the partitions) in Herreria.
• Some plants like Smilax, Dracaena, and Dianella produce berries.

In simple words: The Liliaceae family has diverse flower structures. They usually have six stamens and a superior ovary with three parts. Flowers are often insect-pollinated, and their fruits are commonly capsules or berries.

🎯 Exam Tip: When describing plant families, remember to cover both vegetative and floral characteristics in detail, including the floral formula and any unique features like inflorescence types or fruit types.