Leaf arrangement

 

Leaves can be attached to stems in different arrangements.

 

Plants with only one leaf per node [insert tool tip] are said to have alternate leaves.

 

Alternate leaves
Stem with alternate leaves. [Drawing from Gray 1878]

 

Plants with two leaves per node are said to have opposite leaves.

 

Stem with opposite leaves.
Stem with opposite leaves. [From Gray 1878]

 

Plants with more than two leaves per node are said to have whorled leaves.

 

Plant with whorled leaves.
Plant with whorled leaves. [From Gray 1878]

 

Lastly, some plants produce branches with such short internodes that the leaves look like a bundle of leaves in the axil of a leaf on the main stem. These bundles are called fascicles.

 

Fascicles of leaves.
Fascicles of leaves. [From Gray 1878]

Check your understanding:

Penstemon speciosa
Penstemon speciosa

Hosackia crassifolia
Hosackia crassifolia

Juniper leaves
Juniper leaves

Giant sequoia
Giant sequoia

Chamise
Chamise