1. A Cool Way to Look at Floral Anatomy
Floral Formulas
A Cool Way to
Look at Floral Anatomy

2. Floral Formulas System of notation
Display a ton of information about the structure of a flower
Similar to the notation we used when we learned about grasses
Not standardized

3. Floral Formulas Using the 4 whorls of floral parts as our reference
Calyx (sepals)
Corolla (petals)
Androecium (stamens)
Gynoecium (pistils)

4. Floral Formulas
K = calyx
C = corolla
A = androecium
G = gynoecium

5. Floral Formulas Number of Parts K5 = calyx of 5 sepals
C6 = corolla of 6 petals
A10 = androecium of 10 stamens
G2 = gynoecium of 2 carpels
C0 = corolla missing
A4[5] = androecium usually of 4 stamens, rarely 5

6. Number of Parts (a little more complicated)
Floral Formulas
Number of Parts (a little more complicated)
A4+2 = androecium of 6 stamens, 4 in 1 set, 2 in another
G2-3 = gynoecium of 2 or 3 carpel
Ax = androecium of a low unstable number (about 10-20) stamens
G∞ = gynoecium of high unstable number, more than 20 carpels

7. Floral Formulas Symmetry K = calyx actinomorphic (radially)
C = corolla actinomorphic
Kz = calyx zygomorphic (bilaterally)
Cz = corolla zygomorphic

8. Floral Formulas Fusion of Parts K4 = calyx of 4 separate sepals
C3 = corolla of 3 separate petals
K(4) = calyx of 4 fused sepals
G(2) = gynoecium of 2 fused carpels
G4 = gynoecium of 4 separate carpels
A5 = androecium of 5 stamens fused by their filaments

9. Floral Formulas Fusion of Parts (cont.)
A5G2 = androecium and gynoecium fused by their upper parts
K C A = calyx, corolla, and androecium united into a hypanthium

10. Floral Formulas Ovary Position
G = ovary superior; flower hypogenous or perigynous
G = ovary inferior; flower epigynous
-G- = ovary half-inferior
G = ovary either superior or inferior

11. Floral Formulas
K5 Cz1+(2)+2 A9+1 G1
Given:

12. Floral Formulas Translation K5 Cz1+(2)+2 A9 +1 G1
Calyx of 5 separate sepals
Corolla zygomorphic (bilaterally symmetrical); of 5 petals, 2 fused together, 2 free and forming a pair, and a 5th different from the others
Androecium of 10 stamens, 9 joined by their filaments, the 10th free
Gynoecium unicarpellate, the ovary superior

13. Interpreting Floral Formulas Practice
K(5) Cz(5) A2 or 2+2 G(2)

14. Interpreting Floral Formulas Practice
K3-5 C5 A∞ G(5-8)

15. Interpreting Floral Formulas Practice
K4 C4 A4+2 G(2)

16. Interpreting Floral Formulas Practice
K4 C4 A8 G(4)

17. Interpreting Floral Formulas Practice
K(5) C(5) A5 G(2)

18. Interpreting Floral Formulas Practice
K(5) Cz5 A2+2 G(2)

19. Writing Floral Formulas Practice
Given the following description, write the floral formula:
Flowers bilaterally symmetrical
5 fused sepals
5 fused petals
4 stamens, 2 in one set and 2 in another
Superior ovary, 2 fused carpels
Verbenaceae

20. Writing Floral Formulas Practice
Given the following description, write the floral formula:
4 sepals
4 petals
8 stamen
Calyx, corolla, androecium form a hypanthium
Inferior ovary, 4 fused carpels
Onagraceae

21. Writing Floral Formulas Practice
Given the following description, write the floral formula:
3-5 fused sepals
5 petals
More than 20 fused stamens
Superior ovary, 5-8 fused carpels
Malvaceae

22. Writing Floral Formulas Practice
Given the following description, write the floral formula:
5 fused sepals
5 petals
10-many stamens, sometimes 4
Superior ovary, 1 carpel
Fabaceae
Mimosidae

23. Writing Floral Formulas Practice
Given the following description, write the floral formula:
5 fused sepals
5 petals, zygomorphic
10 stamens
Superior ovary, 1 carpel
Fabaceae
Caesalpinoidea

24. Writing Floral Formulas Practice
Given the following description, write the floral formula:
4-5 fused sepals
4-5 fused petals, zygomorphic
4 stamens in 2 sets of 2
Hypogenous, 2 fused carpels
Acanthaceae

25. Homework For Next Time
Using your notes from previous classes, try to figure out which plant families you have just written the floral formulas for
Bring the names of the families with you to our next meeting