Floral Formulas A Cool Way to Look at

Floral Formulas A Cool Way to Look at Floral Anatomy

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

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

Floral Formulas • • K = calyx C = corolla A = androecium G = gynoecium

Floral Formulas Number of Parts • • • K 5 = calyx of 5 sepals C 6 = corolla of 6 petals A 10 = androecium of 10 stamens G 2 = gynoecium of 2 carpels C 0 = corolla missing A 4[5] = androecium usually of 4 stamens, rarely 5

Floral Formulas Number of Parts (a little more complicated) • A 4+2 = androecium of 6 stamens, 4 in 1 set, 2 in another • G 2 -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

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

Floral Formulas Fusion of Parts • • • K 4 = calyx of 4 separate sepals C 3 = corolla of 3 separate petals K(4) = calyx of 4 fused sepals G(2) = gynoecium of 2 fused carpels G 4 = gynoecium of 4 separate carpels A 5 = androecium of 5 stamens fused by their filaments

Floral Formulas Fusion of Parts (cont. ) • A 5 G 2 = androecium and gynoecium fused by their upper parts • K C A = calyx, corolla, androecium united into a hypanthium

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

Floral Formulas Given: 5 1+(2)+2 9+1 1 K Cz A G

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

Interpreting Floral Formulas Practice (5) K (5) 2 or 2+2 (2) Cz A G

Interpreting Floral Formulas Practice 3 -5 K 5 ∞ (5 -8) C A G

Interpreting Floral Formulas Practice 4 K 4 4+2 (2) C A G

Interpreting Floral Formulas Practice 4 K 4 8 (4) C A G

Interpreting Floral Formulas Practice (5) K (5) 5 (2) C A G

Interpreting Floral Formulas Practice (5) K 5 2+2 (2) Cz A G

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

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

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

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

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

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

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