Arboretum Botanical Glossary

A botanical reference guide of morphological terms, plant structures, propagation techniques, and campus flora definitions.

368 Botanical Definitions 10 Categories A–Z Alphabetical Index Illustrated Growth Forms

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Explore terms organized by botanical structure, morphology, and arboricultural concepts.

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Illustrated Growth Forms & Tree Silhouettes

Compare visual architectures: fastigiate, columnar, weeping, spreading, and more.

Fastigiate Columnar Pendulous / Weeping
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Showing 368 definitions
Synonyms: Petiolate, Petiolates, Petioles, Petiolulate, Petiolulates, Petiolule, Petiolules

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.

Synonyms: Pinnas, Pinnule, Pinnules

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.

Synonyms: Bipinnate, Bipinnates, Pinnatelies, Pinnately, Pinnates, Pinnatifid, Pinnatifids, Pinnatipartite, Pinnatipartites, Pinnatisect, Pinnatisects

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.

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