Botanical Nerd Word: Cotyledon

Bean seedlings showing cotyledons

Cotyledon: A seed leaf; a food storage structure in seeds.*

Cotyledons provide nutrients to the developing plant as it grows its first true leaves. The cotyledons on these bean seedlings (the pair of structures below the leaves) will shrivel and fall off as the plant matures.

*Capon, B. (2005). Botany for gardeners (Revised ed.). Portland: Timber Press.