The distinctive vanillaleaf (Achlys triphylla) is a familiar sight throughout Pacific Northwest woodlands. Its flamboyant umbrellas of triple, wavy-edged leaflets, spiky blooms, and surprising scent as it fades add interest to the forest understory throughout the seasons.
Blooms
The vanillaleaf blooms in late spring and early summer in bottlebrush clusters of tiny flowers. Close inspection reveals the unusual form of these blooms and provides clues to their pollination. Each flower has no petals. What appear to be long, spatulate petals are actually its stamens1A stamen is the male reproductive structure of a flower, consisting of an anther in which pollen is produced and usually a slender filament that attaches it to the flower. An individual flower typically has many stamens. radiating around the base of the ovary2The ovary is the female organ at the base of a plant’s female reproductive structure that produces seed and becomes the fruit or other layer around it. Together with the stigma that receives pollen and is typically attached to the ovary by a style, it comprises the pistil.. The blunt, green ovary protrudes almost directly from the main flower stalk with little to no pedicel3A pedicel is the stem that joins an individual flower to the main stalk of an inflorescence., or, stem of its own. The ovary is topped by a broad stigma4A stigma is the organ at the tip of a flower’s female reproductive structure that receives pollen. It is typically connected to the ovary by a style. These three parts together comprise the pistil. that lacks the slender style that, in most flowers, lofts it into the path of pollinators approaching for nectar. This and the absence of showy petals suggests that the vanillaleaf is pollinated by wind or, perhaps, by pollen-eating insects that carry a dusting of pollen with them as they browse through the flower clusters. The wiry flower stalk is in the form of a scape, or, a leafless inflorescence that rises directly from the ground. It is always separate from the leaf stem, but may look joined as it often leans into the notch between two leaflets. Taller than the leaves, the blooms reach a height of up to 12 inches/30 cm.
Plant Features
The vanillaleaf is a perennial that dies down each autumn and sprouts again the following spring from rhizomes5Rhizomes are thickened stems that grow along or under the soil surface and bear shoots above and roots below. that persist underground from year to year. With these spreading rhizomes, the vanillaleaf forms colonies that sometimes extend into dense ground covers.
While a rhizome may produce several leaves, each leaf emerges above ground individually (like the scape) and appears as a separate plant. A leaf consists of three triangular leaflets joined at the center and fanning atop the stem on a roughly horizontal plane in parasol fashion, creating a pleasant repeating pattern when occurring en masse. They are highly variable in form, having inconsistent numbers of broad teeth or scallops along their outer edges, particularly on the central leaflet. (See “Similar Species” below for more on the edges of the central leaflets.) The leaflets are sometimes even described as having lobes, but are often not divided enough to distinguish subdivisions beyond their wavy edges.
Dew beads readily on the leaves’ water-resistant surfaces and collects along the leaf veins, creating jewel-like patterns that scatter at the slightest movement.
The leaves also possess another appealing feature: not only do they turn golden in autumn, but they exude a sweet odor reminiscent of vanilla as they fade, which persists even when they are completely dry. Native Americans have long hung dried vanillaleaf in their homes for its pleasant scent and insect-repellent properties.
Range and Habitat
The vanillaleaf inhabits the forests of the Vancouver Island, Coast, Olympic, and Cascade ranges from British Columbia south to northern California and extending just east of the Cascade Crest. Look for it in the moist shade of mostly coniferous forest on soil high in organic matter, as in the understory of the accompanying habitat photo.
Similar Species
The California vanillaleaf (A. californica), which shares its range with the vanillaleaf, is considered either the same species (and, therefore, a synonym of A. triphylla), a subspecies of A. triphylla, or a separate species altogether. It is difficult to distinguish, but is more common in coastal areas and can have six to eight and up to twelve teeth on the central leaflet, rather than the three to four common in A. triphylla. The vanillaleaves in the dense population in the accompanying photo, taken in Mt. Rainier National Park, appear to be A. californica.
The vanillaleaf can also be confused with the Pacific trillium (Trillium ovatum) when not in bloom, given its tripartite leaflets. However, they can easily be distinguished by their leaf tips, which, on the vanillaleaf, are broad and scalloped and, on the Pacific trillium, are entire6Having untoothed edges and always end in a single point. Also, the vanillaleaf never bears blooms from its leaf axils, from which the Pacific trillium only flowers.
Gallery
© 2025 Anthony Colburn. Images may not be used or reproduced in any form without express written consent.