Morphology of Flowering Plants

Biology · Class 11

Simulation · Biology · Class 11

Write a floral formula

"Write a floral formula" is a free, interactive Class 11 Biology simulation for NEET, built on the NCERT section "Floral formula and Solanaceae" in Morphology of Flowering Plants. Set a flower's features and watch its floral diagram and formula write themselves: symmetry, sex, whorl counts, fusion brackets, adhesion lines and the superior/inferior bar on G. NEET has asked about this idea 2 times in 10 years of papers.

From the lesson Floral formula and Solanaceae in Morphology of Flowering Plants. Change the values and watch what happens.

Write a floral formulaBiology · Class 11

What it shows

NCERT §5.8–5.9

Set a flower's features and watch its floral diagram and formula write themselves: symmetry, sex, whorl counts, fusion brackets, adhesion lines and the superior/inferior bar on G.

Controls

5 to try

  • Segmentedsymmetry ⊕ / %
  • SliderK, C, A, G counts 0–10
  • Toggle per whorlfused (brackets)
  • Togglestamens on petals (adhesion line)
  • Segmentedovary superior / inferior

Try this

Produce the Solanaceae formula ⊕ ⚥ K(5) C(5) A5 G(2) with epipetalous stamens and a superior ovary, then the mustard formula.

Common mistake

The line under G means inferior ovary.

In NEET

10 years of papers

Asked 2 times in 10 years of NEET.

See the past questions: Morphology of Flowering Plants (chapter)

The idea behind it

NCERT §5.8, §5.9, Figures 5.16–5.17

  • A semi-technical description is short, simple and scientific, and follows a fixed order: habit, then vegetative characters (root, stem, leaves), then floral characters (inflorescence, flower parts), then a floral diagram and a floral formula.
  • Floral formula symbols: Br bracteate, K calyx, C corolla, P perianth, A androecium, G gynoecium, ⊕ actinomorphic, % zygomorphic, ⚥ bisexual, ♂ male, ♀ female. A line under G means a superior ovary; a line over G means an inferior ovary.
  • Fusion within a whorl is shown by putting the number in brackets, e.g. C(5). Adhesion between whorls is shown by a line drawn over the symbols concerned, e.g. over C and A for epipetalous stamens.
  • A floral diagram shows the number of parts, their arrangement and their relation to one another. A dot at the top marks the mother axis; calyx is the outermost ring and gynoecium the centre.
  • The worked example (Figure 5.16) is mustard, family Brassicaceae: ⊕ ⚥ K2+2 C4 A2+4 G(2), ovary superior.
  • Solanaceae, the potato family, is a large family spread through the tropics, subtropics and temperate zones. Example figured: Solanum nigrum (makoi).
  • Vegetative: mostly herbs and shrubs, rarely small trees. Stem herbaceous (rarely woody); potato (Solanum tuberosum) has an underground stem. Leaves alternate and simple (rarely pinnately compound), without stipules (exstipulate), with reticulate venation.
  • Floral: inflorescence solitary, axillary or cymose; flower bisexual and actinomorphic; five united, persistent sepals and five united petals, both valvate; five epipetalous stamens; bicarpellary, obliquely placed, syncarpous, superior, bilocular ovary with a swollen placenta bearing many ovules (axile). Fruit berry or capsule; seeds many, endospermous.
  • Floral formula: ⊕ ⚥ K(5) C(5) A5 G(2), with a line joining C and A (epipetalous) and the ovary superior.
  • Uses: tomato, brinjal and potato are foods; chilli is a spice; belladonna and ashwagandha are medicines; tobacco is fumigatory; petunia is an ornamental.

Questions

4 answers

What does the "Write a floral formula" simulation show?
Set a flower's features and watch its floral diagram and formula write themselves: symmetry, sex, whorl counts, fusion brackets, adhesion lines and the superior/inferior bar on G.
What mistake does the "Write a floral formula" simulation fix?
A common mistake it clears up: the line under G means inferior ovary.
Has NEET asked about this idea?
Yes. NEET has asked about this idea 2 times in 10 years of papers.
Is this simulation free?
Yes. It is free and runs in the browser on a phone or a laptop. It belongs to the lesson "Floral formula and Solanaceae" in Morphology of Flowering Plants (Class 11 Biology).

Embed this simulation

Free, with a link back

Teaching this idea? Put the simulation on your own page or LMS with this code.