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The fascinating world of trout lilies
Newts from the Field is a seasonal installment written by Wildlands Ecology Director Shelby Perry, bringing you the wonders of nature from out in the wilderness.

I recently listened to an entire audiobook and spent many google-hours trying to better understand plastic.  I knew it to be a petroleum product, and to be ubiquitous in my life with an array of recycling options from simple to impossible, but I’ll admit that I understood little beyond that.  Plastic, it turns out, is not one thing, but dozens.  Novel combinations of waste materials generated in the petroleum refining process with various chemical additives to achieve its myriad textures and forms, plastic came alive for me in a whole new (and concerning) way!

Riding high on that wave of discovery, I decided to keep digging, this time into that utterly common–yet surprisingly fascinating–harbinger of spring: the trout lily.

The most common trout lily in the Northeast is the yellow variety known by the specific epithet Erythronium americanumErythronium, somewhat paradoxically, comes from the Greek word meaning “red” – so named for another member of the genus that has rosy pink petals.  Our local version tends to have yellow flowers – though sometimes the back of the flower or the pollen-bearing structures (anthers) can be red.

The leaves of a trout lily show up well before the flower, and those little mottled green and red-brown single leaves are almost always the very first plants I spot growing in the woods each spring.  Poking up right through the leaf litter, trout lilies come up as early as they can to take advantage of the spring sunshine on the forest floor before trees leaf out.  They pack much of their life cycle into that brief period between snow melt and leaf out, and begin to decline once tree leaves start to shade them out.

So-named for how their mottled leaves resemble the dappled sides of our native brook trout, trout lilies come up as either a single leaf or a double. Only the double-leaved plants flower, and their flowers are critical sources of pollen and nectar for foraging queen bumblebees and other early-season pollinators.  After a flower has been pollenated, seeds develop and mature around June.  Their seeds are spread at least in part by myrmecochory, from the Greek for “circular dance” and meaning that they are dispersed by ants.

Mature seeds have an attached structure known as an “elaiosome,” which is really just a fancy word for a tasty snack.  The ants will drag seeds down into their nests, where they will feed the elaiosome to their larvae and discard the seed intact.  This is beneficial for both the ants, who get a nutrient dense meal, and the seeds, who essentially get planted in the relative safety and rich soil of an ant nest’s compost pile.

Seeds and ants are not the only way trout lilies spread, though.  Beneath each plant, below ground, is a small food-storage structure similar to a bulb called a corm.  These white structures are said to have inspired the trout lily’s other common name, dog toothed violet, because of their supposed resemblance to the fang of a dog.  These corms will extend root-like structures called “stolons” into the surrounding soil, at the end of the stolons a bud called a “dropper” will form.  Droppers can be anywhere from deep in the soil below the parent corm, to just threading along under leaf litter at the soil surface. They will eventually grow into new, genetically identical corms to the parent and the stolon will wither away. Over time, this propagation method forms a massive clonal colony of trout lilies.

Botanists still disagree on whether these clonal plants ever grow two leaves and flower, or if they just stay single leaf clones, leaving only the plants grown via seed to flower.  And it takes baby trout lilies an average of seven years to reach sexual maturity and be able to flower, so no matter how they reproduce, every plant spends its first several years as a single leaf and most colonies are composed mostly of the non-flowering single-leaf plants.

As corms send out stolons that grow into corms that send out stolons that grow into corms (and so on!) you can see how over time a single plant could soon become dozens and then hundreds.  In fact, some trout lily colonies are over a hundred years old!  Protecting old forests also protects all of the plants and animals that depend on prolonged periods without disturbance to thrive, including centuries old trout lily groves.

So this spring, as tiny trout lily leaves start to carpet the forest floor and their cheerful yellow flowers curl back their petals in spring delight, I hope you will see these common forest friends with new eyes.  Perhaps you are admiring the leaf of a corm that is older than you are, perhaps older even than the trees above it.  Perhaps this trout lily colony has turned its flowers into the spring sunshine in that very spot for a hundred years or more.

Photography by Shelby Perry