Semi-Technical Description of a Flowering Plant: The plant is described beginning with its habit, vegetative characters such as roots, stem and leaves and then floral characters inflorescence and flower parts. After describing various parts of the plant, a floral diagram and a floral formula are presented, which is represented by some symbols. Fusion is shown by enclosing the figure in a bracket, and adhesion is denoted by a line drawn over the floral portion symbols. A floral diagram shows the number of parts in a flower, how they are arranged, and how they are related to one another. Read on more about the semi-technical description of a flowering plant.

What is a Semi-Technical Description of a Flowering Plant?

1. The morphological feature is used to describe a plant.
2. The description must be clear, scientific, and conveyed in a logical order.
3. The plant’s habit, vegetative characters (roots, stem, leaves), flower characters, inflorescence, and floral characters are all detailed.
4. Following the description, the flower formula and diagram are shown.

The following is the orderly procedure of describing a plant technically or botanically.

1. Habit

We must consider the plant’s life span when defining its habit, and we must use the terminology annual for a plant that lives for one year, biennial for a plant that lives for two years, and perennial for a plant that lives for many years. In the habit category, we must also consider the plant’s nature, size, and overall appearance. We must use the terms herb, shrub, or tree to describe the plant’s nature. In the habit description of the plant, we can indicate the plant’s actual size, whether it’s conical shaped, erect, climbing, twining, and so on.

The terms listed below should be used to describe the habit section of the botanical description.

A. Annual, biennial, or perennial
B. Herb, shrub, or tree
C. Erect, climbing, or twining

2. Roots

We must determine whether the root system is a tap root system or a fibrous root system when characterising the roots. A bulky mother root with secondary and tertiary roots with root hairs can be found in a tap root system. There is no mother root in a fibrous root system; rather, many thin fibre-like roots emerge from the stem’s base. If the roots are visible in that particular plant, we must additionally note any root modifications.

The following are the actual terms to be used for describing the root system part of the botanical description.

A. Tap or fibrous root system
B. Roots showing special modifications like tuberous, nodular, pneumatophores, etc.

3. Stem

We must determine whether the stem is green herbaceous or woody while characterising it. We must also look at the stem’s growth direction, shape, internal appearance, colour, covering (hairy or smooth), and any alterations identified in the stem.

The terminology used to describe the stem section in the botanical description are as follows.

A. Herbaceous, Shrubby, Woody
B. The stem’s direction of growth (erect or creeping or climbing or twining or underground)
C. Dimensions (round or cylindrical or square or ribbed)
D. The nature of the stem (solid or hollow)
E. The colouration of the stem (green or brown or dark brown
F. Stem covering (smooth or glabrous or hairy)
G. Modification (phylloclade or cladode etc.).

4. Leaves

For composing the botanical description, the following observations must be taken while describing the plant’s leaf. The pattern of arrangement of leaves at the nodes of the plant’s stem is known as phyllotaxy. We must look to see if the leaf is directly attached to the plant’s stem or if it is attached to the plant’s petiole. The shape of the leaf, the venation of the leaf, the edge of the leaf, the apex of the leaf, the base of the leaf, the texture of the leaf, the surface of the leaf, and any alterations of the leaf must all be observed.

The terminology used to describe the leaf in the botanical description are as follows.

A. Phyllotaxy is the scientific term for the study of plants (alternate or opposite or whorled or spiral)
B. Insertion (radical or cauline, petiolate or sessile)
C. The type of leaf (simple or compound)
D. A leaf is shaped like this (lanceolate or elliptical or obovate or mucronate, etc.)
E. Leaf Vegetation (unicostate or multicostate)
F. A leaf’s margin is the edge of the leaf (entire or serrate or repand or dentate or crenate or spiny, etc.)
G. A leaf’s apex  (acute or acuminate or mucronate or cuspidate or emarginate or obtuse, etc.)
H. The leaf’s base (stipulate or exstipulate)
I. The leaf’s surface texture (coriaceous or succulent or hygrophytic or herbaceous)
J. The leaf’s surface (pubescent or hispid or glabrous or glaucous or viscose or scabrous, etc.)
K. Modification (pitcher or spines or thorns or tendrils, etc.)

5. Inflorescence

A. Inflorescences can be either determinate or indeterminate.
B. It is necessary to specify the type of inflorescence (racemose, cymose, mixed, or specific type).

6. Flower

The terminology used to describe the flower in the botanical description is as follows.

A. Bracts present or absent (bracteate or ebracteate)
B. The stalk of the flower is present or absent (pedicellate or sessile)
C. All of the flower’s whorls are present or absent (complete or incomplete)
D. Male and female parts can be found together or separately (bisexual or unisexual)
E. On the same or distinct plants, male and female flowers can be found (monoecious or dioecious)
F. The flower’s symmetry (actinomorphic or zygomorphic or asymmetric)
G. The flower organs are arranged in a unique way (acyclic or cyclic, or hemicyclic)
H. Merosity(dimerous or trimerous or tetramerous or pentamerous or isomerous)
I. Insertion (hypogynous or epigynous or perigynous)
J. The flower’s appearance (bell-shaped or tubular etc.)
K. The presence of nectar guides, thalamus speciality.

7. Calyx

A. The number of sepals on a flower
B. Sepals are either or united in cohesion (polysepalous or gamosepalous)
C. Whether superior or inferior
D. Aestivation is the arrangement of sepals in the flower’s bud stage (open or valvate or imbricate or twisted)
E. Duration of time (caducous or deciduous etc.)
F. Whether Epicalyx

8. Corolla

A. The number of petals
B. Petals are either or joined in their cohesion (polypetalous or gamopetalous)
C. Whether superior or inferior,
D. Petals for the arrangement (cruciform or rosaceous or papilionaceous or tubular or infundibuliform or ligulate or bilabiate etc.)
E. Dimensions (regular or irregular)
F. Size
G. Colour
H. Texture
I. Duration
J. Odour

9. Perianth

When the sepals and petals cannot be distinguished, we must describe the perianth; otherwise, there is no need. Perianth (sepaloid or petaloid); other features, such as calyx and corolla, must be described.

10. Androecium

A. Number of stamens
B. Cohesion- the union of stamens (monadelphous, diadelphous, polyadelphous, syngenesious, or synandrous)
C. Adhesion- stamens joined to sepals, petals, or gynoecium (episepalous, epipetalous, epiphyllous, or gynandrous)
D. Superior or inferior
E. Relative stamen lengths (didynamous or t Fixation refers to how the filament is attached to the anther (adnate, basifixed, dorsifixed, or versatile)
F. Dehiscence refers to how the anther is broken to release pollen (longitudinal or transverse or porous or valvular)

11. Gynoecium

The terminology used to describe the gynoecium in the botanical description are as follows.

A. The number of carpels (monocarpellary or bi-carpellary or tricarpellary or tricarpellary or Penta-carpellary or multicarpellary)
B. Carpels or fused (apocarpous or syncarpous)
C. Adhesion (with androecium)
D. Style position (terminal style or lateral style or gynobasic style)
E. Stigma lobes (unified or bifid or trifid or tetrafid or pentafid or multifid)
F. Modification of stigma (capitate or forked or feathery, etc.)
G. Ovary position (superior or inferior)
H. The number of locules in the ovary (unilocular or bilocular or trilocular or tetra locular or pentalocular or multilocular)
I. Placentation- way of arrangement of ovules on the ovary (axile or basal or marginal or parietal, etc.).

12. Fruit

The following are the actual terms to be used for describing the fruit of a plant botanically.

A. The fruit is true or false
B. Fruit breaks or not (dehiscent or indehiscent)
C. Dry or fleshy
D. Type of fruit (legume or caryopsis or follicle or siliqua etc.)

13. Seed

The following are the characters to be used for explaining the seed of a plant.

A. Count of seeds
B. Endospermic or non-endospermic seeds are available.
C. The seed’s form; the seed’s dispersal method
D. The seed’s germination type.

Floral Formula

It indicates the number, cohesiveness, and adherence of the distinct whorls of the flower. The floral formula is represented by a series of symbols.

Fig: Floral formula and floral diagram

1. ♀️ – Female
2. ♂ – Male
3. ⚥ – Bisexual
4. ⨁ – Actinomorphic
5. ％ – Zygomorphic
6. Br – Bracteate
7. Ebr – Ebracteate
8. Brl – Bracteolate
9. K – Calyx
10. C – Corolla
11. P – Perianth
12. A – Androecium
13. G – Gynoecium
14. G – Superior Ovary
15. Ḡ – Inferior Ovary
16. ( ) – Fused/Gamo
17. ⌒ – Epipetalous/Epiphyllus

Symbols for Number of Floral Parts

At the right foot of the symbol, the number of flower parts is written. They are bracketed if they are fused. The following are some examples.

Floral Diagram

A floral diagram is a diagram of a flower that shows the number of elements in each whorl, their arrangement, relationship to one another, cohesion and adhesion, and position relative to the mother axis. The following characteristics are depicted in the floral diagram:

1. A dot on top of the floral diagram represents the mother axis.
2. The calyx is the outermost whorl. The gynoecium is the innermost whorl.
3. Presence or Absence of the bract and the bracteoles
4. The position of odd sepals.
5. Arrangement and the number of floral leaves in relation to each other.
6. The adhesion and cohesion of floral leaves.
7. Sepal and Petal’s Aestivation.
8. Flower Symmetry
9. Nature of Anther: Monothecous, Bithecous
10. Number of locules in the ovary
11. Placentation types

Fig: Floral Diagram

Description of One Family

Fabaceae (Papilionaceae)

1. Habit: Herbs, shrubs, trees, climbers.
2. Root: Taproot, root nodules containing nitrogen-fixing bacteria Rhizobium.
3. Stem: Herbaceous, woody, erect or climbing.
4. Leaves: Alternate, pinnately compound, rarely simple, pulvinate leaf base, stipulate, reticulate venation.
5. Inflorescence: Raceme
6. Flower: Bisexual, zygomorphic, polypetalous, papilionaceous.
7. Calyx: Sepals 5, gamosepalous, imbricate aestivation.
8. Corolla: Petals 5,, vexillary aestivation.
9. Androecium: Stamens 10, diadelphous – (9)+1, dithecous.
10. Gynoecium: Monocarpellary, unilocular, superior, marginal placentation.
11. Fruit: Legume or pod

Fig: Floral Structure and diagram of Fabaceae

Floral Formula and Floral Diagram

Fig: Floral diagram of Fabaceae

Summary

For easy identification and classification, a flowering plant’s description contains vegetative and floral traits, the floral formula, and a floral diagram. A flowering plant’s technical description must be written in scientific language and must be basic, concise, and sequential. A flower’s symmetry, sex, calyx, corolla, perianth, androecium, gynoecium, bracts, bracteoles, staminodes, pistillodes, and the number of sepals, petals, stamens, and carpels are all represented by a series of symbols in the floral formula. With the use of symbols, the formula also explains cohesion and adhesion inside parts of the whorls and between whorls. In most cases, the floral formula is accompanied by a floral diagram. The floral diagram depicts a flower’s cross-section and includes data on sex, symmetry, bracts, bracteoles, and the number of floral whorls.

Frequently Asked Questions (FAQs)

Q.1. What is a semi-technical description of a flowering plant?
Ans: In a semi-technical description of the flowering plant, its habits, vegetative characters such as roots, stems, and leaves are discussed first, followed by floral characters such as inflorescence and flower components. Following a description of the plant’s different sections, a floral diagram and a floral formula are given, both of which are represented by symbols.

Q.2. What is the floral formula of a flowering plant?
Ans: The floral formula is represented by a series of symbols and gives information about a flower such as its symmetry, sex, calyx, corolla, perianth, androecium, gynoecium, bracts, bracteoles, staminodes, pistillodes and the number of sepals, petals, stamens and carpels.

Q.3. What is a floral diagram of a flowering plant?
Ans: A floral diagram is a diagram of a flower that shows the number of elements in each whorl, their arrangement, relationship to one another, cohesion and adhesion, and position relative to the mother axis.

Q.4. Which structural features are used to describe a flowering plant?
Ans: Sepals, petals, stamens, and carpels are the four primary parts of most flowers. The stamens are the male part of the flower, while the carpels are the female part. The majority of flowers are hermaphrodites, meaning they have both male and female parts. Others may be masculine or female and contain one of the two parts.