spadix

A spadix is a type of inflorescence characteristic of many plants in the family Araceae. It consists of a thick, fleshy central axis bearing numerous tiny flowers arranged along its length, often densely packed around the axis. In many species the spadix is enclosed by a spathe, a leaf-like bract that forms a hood or sheath around the inflorescence.

The flowers on a spadix are typically small and often unisexual, with male flowers usually occupying the upper portion and female flowers toward the base; sterile or reduced flowers may occur between or at the ends. This arrangement can assist in pollination by guiding visitors to contact the reproductive structures. In some Araceae, the inflorescence features thermogenesis and emits scents to attract pollinators such as flies, occasionally trapping them briefly to ensure pollination before release.

Common examples of spadix-bearing plants include Arum, Anthurium, Philodendron, and Zantedeschia (calla lilies). They may appear in evergreen climbers, rhizomatous perennials, or herbaceous plants, often with a striking spathe that helps attract pollinators or serves an ornamental function. After successful pollination, the spadix bears a cluster of berries, developing from the fertilized flowers.

In horticulture and gardening, spadix-bearing plants are valued for their ornamental inflorescences, dramatic foliage, and diverse forms. The term spadix is also used more broadly to describe similar inflorescence structures in related plant groups, though it is most commonly associated with Araceae.