What is a Leaflet in Biology ?

In this video, we explain the Leaflet in Biology — a single segment of a compound leaf that looks like a small standalone leaf but is not an independent leaf anatomically. Multiple leaflets share one petiole (the leaf stalk) and together form a single leaf organ; they articulate on a common axis (the rachis in pinnate leaves, or radiate from a point in palmate leaves). The key diagnostic feature is that a leaflet lacks an axillary bud at its base, whereas a true leaf attaches to the stem with an axillary bud in its axil. Leaflets can be entire, lobed, serrate, or dissected; their venation patterns and cuticle traits mirror those of simple leaves but are tuned for flexibility, light capture, gas exchange, and mechanical resilience. Compound architectures (pinnate, bipinnate, palmate, trifoliate) distribute mass to reduce wind damage, modulate boundary layers, and allow selective shedding (abscission at pulvini or petiolules) without losing the whole leaf. Developmentally, leaflet identity is patterned by hormonal and genetic controls (notably auxin dynamics and KNOX/ARP networks), enabling remarkable diversity across legumes, ferns, and many woody plants. In short, a leaflet is the functional photosynthetic module within a compound leaf, optimized for performance while remaining part of a larger, integrated leaf system.
#Leaflet #PlantMorphology #Botany #PlantAnatomy #PlantBiology #SciWords

Видео What is a Leaflet in Biology ? канала Sciwords