A botanical reference guide of morphological terms, plant structures, propagation techniques, and campus flora definitions.
Explore terms organized by botanical structure, morphology, and arboricultural concepts.
Species The most basic rank in plant classification, identifying a specific kind of plant whose members share the same characteristics and can naturally reproduce with one another. A species is named by two words—the genus followed by the species epithet; for example, Quercus rubra is the species commonly known as red oak. While a genus groups related plants together, the species pinpoints one particular kind…
Sphaerocyst A round swollen cell, usually formed in clusters, found in the fruiting bodies of some mushrooms, characteristically found in the Russulaceae
Spike A flowering stem with flowers directly attached. This feature helps explain how flowers are arranged, how pollination happens, or how seeds begin to form.
Spore A simple reproductive body used by ferns, fungi, and other lower plants that do not produce seeds
Spur A specialized short twig of certain fruit trees on which flowers and fruit are borne. A thin spike-like part attached to a flower or other structure.
Squarrose With branches spreading and recurved at the ends. This feature helps describe plant form, function, or identification.
Standard A plant that has been artificially trained to a single-stemmed upright form
Stellate Star-shaped. This feature helps describe plant form, function, or identification.
Sterile Describing a flower that cannot produce viable seeds. This feature helps explain how flowers are arranged, how pollination happens, or how seeds begin to form.
Stipule Growths attached to the base of a leaf stalk, usually one at each side, often ear-like
The Purdue Arboretum is a collaboration between the Department of Horticulture and Landscape Architecture and Administrative Operations