floral formula

views updated May 18 2018

floral formula A conventional method for recording the structure of a flower. It uses a series of capital letters to identify parts: K = calyx; C = corolla; A = androecium; G = gynoecium. The number of components in each is indicated by a number; if the number exceeds 12, the symbol ∝ (infinity) is used. If the parts are fused the number is enclosed in brackets. If 1 whorl is fused to the next, they are enclosed by a single bracket drawn horizontally above them. The position of the ovary is indicated by a line; this is below the number following G if the ovary is superior and above it if the ovary is inferior. The formula is preceded by the symbol ⌖ if the flower is actinomorphic and or ↑ if it is zygomorphic.

floral formula

views updated Jun 27 2018

floral formula A summary of the structure and components of a flower using symbols and numbers. The symbols representing symmetry include  (for actinomorphy) and , ↓, or ↑ (for zygomorphy). The parts of the flower are represented by K (for calyx), C (for corolla), P (for perianth), A (for androecium), and G (for gynoecium). These are followed by numbers indicating the number of parts in each whorl (e.g. K5 indicates a calyx of five sepals); ∞ indicates an indefinite number of parts (more than 12). If the parts are fused the number is in parentheses; if they are in separate groups or whorls the number is split (e.g. C2 + 2 indicates a corolla of two whorls each of two petals). The symbol G has a line above it to indicate an inferior ovary and a line beneath it to indicate a superior ovary. For example, the buttercup flower has the following floral formula:  K5 C5 A∞ G̱∞,

i.e. it has a calyx of five sepals, a corolla of five petals, an androecium of many stamens, and a superior ovary consisting of many carpels.