Due to their unusual ecology and form, gnome plants (Hemitomes congestum) are easy to miss. They are mycoheterotrophs, or, plants that draw nutrients from fungi in the soil, rather than producing it themselves from sunlight. Accordingly, they have dispensed with all above-ground, plant-like structures that would ordinarily possess chlorophyll to generate energy of their own. The only part of the gnome plant to emerge from its subterranean home is the bouquet of blooms required for reproduction.
Counterintuitively, although gnome plants are parasites, they and other mycoheterotrophs are thought to contribute to the forest’s overall health by signalling the vast network of fungi and roots to transfer nutrients where they are needed most. Not surprisingly, gnome plants are typically found in conifer woodlands, usually in deep shade on patches of bare or mossy ground where little else grows. As unusual as gnome plants are, their evolution of mycoheterotrophy is not uncommon, as several other Pacific Northwest plants have evolved the same adaptation, including pinedrops, pinesaps, ghost pipes, and coralroot orchids.
The gnome plant’s vestigial leaves have been reduced to small scales along the underground flower stalk and may be visible as slightly fringed bracts1Bracts are leaves that occur within or just below a flower cluster and often differ in size, form, and sometimes color from ordinary leaves. ringing the flower buds before they open. While all parts of the gnome plant can range from shell pink through yellowed ivory and pearly white, the bracts tend to display the most intense color, sometimes approaching a deep shade of vermilion.
Prominent floral features are the large, yellow stigma2The stigma is the tip of the pistil (the female organ of the flower) that receives pollen. surrounded by the densely hairy interior of the corolla that is formed by four or five partially fused petals. Although the gnome plant’s pollinators are not known, it has been suggested that the flowers’ hairy throats block small insects from crawling in and taking the nectar that attracts long-tongued creatures, e.g., moths, that may be its preferred pollinators. After pollination, the stigma turns black.
In the Pacific Northwest, look for gnome plants in mid-summer. They are perennial, but, within a couple short weeks, have shrivelled and gone for the remainder of the year. If pollinated, they bear white, berry-like fruits, dotted on the ends with remnants of the blackened stigmas. Because the fruits are fleshy with a pungent odor variously described as “musky” and “cheesy,” it is assumed that seed dispersal is achieved through consumption of the fruits by creatures attracted to their distinctive scent.
Most resources describe gnome plants as rare or uncommon, although they may be locally abundant. They range along the Pacific and Salish coasts from British Columbia to California.
Typical gnome plant habitat on bare or mossy soil beneath conifers:
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