Definition of dicotyledon in US English:



  • A flowering plant with an embryo that bears two cotyledons (seed leaves). Dicotyledons constitute the larger of the two great divisions of flowering plants, and typically have broad, stalked leaves with netlike veins (e.g., daisies, hawthorns, oaks).

    Class Dicotyledoneae (or -donae, -dones; sometimes Magnoliopsida), subdivision Angiospermae

    Compare with monocotyledon
    • ‘The broad differences between halophytic monocotyledons and dicotyledons have been attributed to differences in water content and hence vacuolar volume.’
    • ‘However, it should be kept in mind that young leaves of dicotyledons are more heterogenous as to cell age, than sections of a monocotyledon leaf.’
    • ‘Besides this constitutive system, iron reductases have been described in dicotyledons and non-grass monocotyledons that reduce iron prior to uptake.’
    • ‘Thus, the phloem is neither ‘interxylary’ nor ‘included’ in dicotyledons with successive cambia.’
    • ‘Monocotyledons, such as maize, have a single cotyledon; dicotyledons, such as Arabidopsis, have two.’


Early 18th century: from modern Latin dicotyledones (plural), from di- ‘two’ + cotyledon (see cotyledon).