Key to Floral Formulas
return to family index
Ca = calyx: or whorl of sepals
Co = corolla; or whorl of petals
CaCo = perianth; if sepals and petals are alike termed 'tepals'.
A = Androecium; or whorl of stamens.
G = Gynoecium; or ovary bearing carpels.
X = number of sepals
X = number of petals
X = number of stamens
X = number of carpels: if one, termed 'monocarpous', if two or more and free or distinct, termed 'apocarpous', if two or more and fused, termed 'syncarpous' or connate.
X - X = variation in number in that family
X = X = Like floral parts in two whorls
= fully fused or connate, especially in reference to the carpels of the gynoecium. If carpel # has no fusion symbol, carpels are free and distinct.
= apically fused or connate
= basally fused or connate
= fully distinct or fused; variation within a family
= male unisexual flower
= female unisexual flower
* = staminode; a sterile stamen
= adnate; or fusion of two different floral whorls
= 'hypanthium' when all whorls are present. Especially frequent in the Rosidae. The floral whorls are perigynous to the gynoecium, which is still considered superior to them.
= ovary inferior to insertion point of the other whorls. The floral whorls are epigynous to the gynoecium.
= ovary superior to insertion point of other floral whorls. The floral whorls are hypogenous to the gynoecium.
= ovary inferior to superior - variation exists within the family; or half inferior.