Leaf Arrangement

This page is from the Colorado State University Extension Service website.

Leaf Features

  • Leaf blade – Flattened part of the leaf 
  • Petiole – Leaf stalk
  • Stipules – Leaf-like appendages at the base of the leaf.

Leaf Arrangement on Stems

  • Alternate – Arranged in staggered fashion along stem (willow)
  • Opposite – Pair of leaves arranged across from each other on stem (maple)
  • Whorled – Arranged in a ring (catalpa)
  • Rosette – Spiral cluster of leaves arranged at the base (or crown) (dandelion)

Leaflet Arrangement on Petiole 

  • Simple – Leaf blade is one continuous unit (cherry, maple, and elm)
  • Compound – Several leaflets arise from the same petiole
  • Pinnately compound – Leaflets arranged on both sides of a common rachis (leaf stalk), like a feather (mountain ash)
  • Palmately compound – Leaflets radiate from one central point (Ohio buckeye and horse chestnut)
  • Double pinnately compound – Double set of compound leaflets
© Tom Lebsack 2020