Arboretum Botanical Glossary

Petaloid Petal-like in appearance. This feature helps explain how flowers are arranged, how pollination happens, or how seeds begin to form.

Petiole Leaf-stalk. Botanists use this feature to describe leaf shape, surface, edge, or arrangement, which helps with plant identification. Did you know? The petiole helps position the leaf blade so it can capture light efficiently without shading nearby leaves.

Phenolic Having an odor of the chemical phenol (sickeningly sweet and acrid)

Pinna A single leaflet of a pinnately divided (feather-like) leaf. Botanists use this feature to describe leaf shape, surface, edge, or arrangement, which helps with plant identification.

Pinnate Having parts arranged like a feather, symmetrically on either side of a central rib - often used to describe compound leaves. Did you know? Ash, walnut, hickory, and rose leaves are pinnate, with leaflets arranged along a central stalk.

Pith The spongelike substance in the center of a stem. This feature helps describe plant support, storage, water movement, or vegetative spread.

Pleaching A formal technique for training trees or shrubs in which the branches are interwoven and plaited together to form a hedge or arbor

Plica A plait or fold. This feature helps describe plant form, function, or identification.

Plumose Like a feather. This feature helps describe plant form, function, or identification.

Pollarding A pruning technique in which the main limbs of a tree are cut back each year to very short stubs