Description of Families
Fabaceae, Solanaceae and Liliaceae described in semi-technical language. (Biology › Morphology of Flowering Plants, NEET UG syllabus.)
What is Description of Families?
A type of aestivation where the largest petal (standard) overlaps two lateral petals (wings), which in turn overlap two smallest anterior petals (keel). Characteristic of Fabaceae.
Key formula / rule: Floral Formula of Fabaceae
Key points
- Describe the characteristic vegetative and floral features of Fabaceae, Solanaceae, and Liliaceae.
- Identify common examples of plants belonging to each family.
- Write and interpret the floral formula for each family.
- Recognize the economic importance of each family.
Common exam trap
Confusing vexillary aestivation (Fabaceae) with valvate aestivation (Solanaceae, Liliaceae).
Definitions
- Term
Vexillary Aestivation
- Meaning
A type of aestivation where the largest petal (standard) overlaps two lateral petals (wings), which in turn overlap two smallest anterior petals (keel). Characteristic of Fabaceae.
- Term
Diadelphous
- Meaning
A condition where stamens are united into two bundles. For example, 9 stamens fused and 1 free in Fabaceae (9+1).
- Term
Epipetalous
- Meaning
A condition where stamens are attached to the petals, as seen in Solanaceae.
- Term
Epitepalous
- Meaning
A condition where stamens are attached to the tepals (perianth members), as seen in Liliaceae.
- Term
Perianth
- Meaning
When the calyx and corolla are not distinct, the collective term for the floral envelope is perianth, and its individual members are called tepals.
- Term
Oblique Septum
- Meaning
A characteristic feature of the Solanaceae ovary where the septum dividing the two carpels is placed diagonally, not straight.
Learning objectives
Describe the characteristic vegetative and floral features of Fabaceae, Solanaceae, and Liliaceae.
Identify common examples of plants belonging to each family.
Write and interpret the floral formula for each family.
Recognize the economic importance of each family.
Formulae
- Name
Floral Formula of Fabaceae
- Note
Zygomorphic, bisexual, 5 fused sepals, 5 petals (standard, wings, keel), 10 stamens (9 fused, 1 free), superior monocarpellary ovary.
- Expression
% ⚥ K(5) C1+2+(2) A(9)+1 G1
- Name
Floral Formula of Solanaceae
- Note
Actinomorphic, bisexual, 5 fused sepals, 5 fused petals, 5 epipetalous stamens, superior bicarpellary ovary.
- Expression
⊕ ⚥ K(5) C(5) A5 G(2)
- Name
Floral Formula of Liliaceae
- Note
Bracteate, actinomorphic, bisexual, perianth of 6 tepals (3+3), 6 epitepalous stamens (3+3), superior tricarpellary ovary.
- Expression
Br ⊕ ⚥ P3+3 A3+3 G(3)
Prerequisites
Basic understanding of plant morphology (root, stem, leaf, flower parts).
Knowledge of floral terms (calyx, corolla, androecium, gynoecium, aestivation, placentation).
Ability to interpret and write floral formulae and diagrams.
Common mistakes
Confusing vexillary aestivation (Fabaceae) with valvate aestivation (Solanaceae, Liliaceae).
Incorrectly writing or interpreting floral formulae, especially the arrangement of stamens (diadelphous, epipetalous, epitepalous).
Misidentifying examples of plants belonging to different families.
Forgetting the unique features like the oblique septum in Solanaceae or root nodules in Fabaceae.
Keywords
Fabaceae
Solanaceae
Liliaceae
Floral Formula
Floral Diagram
Vexillary Aestivation
Diadelphous
Epipetalous
Epitepalous
Perianth
Oblique Septum
Legume
Berry
Capsule
Nitrogen Fixation
Economic Importance
NEET Biology
Practice preview
A persistent calyx, which remains even after fruit formation, is a notable feature of which plant family?…
easy
A plant exhibits alternate, simple, exstipulate leaves with reticulate venation. Its flowers are actinomorphic, bisexual, with a persistent calyx and epipetalous stamens. The fruit is a berry. To which family does this p…
medium
A plant has a floral formula represented as Br ⊕ ⚥ P(3+3) A3+3 G(3), superior. Which of the following families does this floral formula represent?…
hard