By Lee Casebere
Many natural history buffs look forward to the transition from winter to spring, and relish days afield in the awakening woods to witness the annual grand flush of spring ephemeral wildflowers. Among the earliest to bloom is the dainty snow trillium (Trillium nivale). Unfortunately, it is quite rare and local in its distribution despite being found by the hundreds or thousands in some populations. Many seasoned wildflower enthusiasts have rarely seen it. In his book Flora of Indiana (1940), famous Indiana botanist Charles Deam says this about its habitat: “In rocky or gravelly soil in protected places on steep, wooded slopes, usually along or near streams.” It prefers soils or rocky substrates that are neutral or basic (alkaline) so areas with limestone bedrock or soils with calcareous gravels and sands are where to look for it, not areas with acidic sandstone bedrock or acidic soils.
A confusing factor related to this statement is that some of the best-known populations in the state are actually found where acidic sandstone bedrock is overlain by calcareous glacial drift. Snow trillium usually grows where surficial leaf litter and deep leaf mold are minimal, and soils are often raw and bare and show evidence of erosion. Where exposed bedrock is present, it sometimes grows out of cracks in the rocks. The trillium blooms when the first flowers come up in spring such as hepatica and harbinger-of-spring (Erigenia bulbosa), and these two species are often closely associated with it. Most populations in Indiana flower sometime during the month of March.
Despite its rare and local distribution, snow trillium is found in several state parks and nature preserves.
One of the easiest and best populations to see is at Turkey Run SP. Just after crossing the suspension bridge, head up-river along Trail 4. As the trail ascends the slope, hundreds of snow trillium can be seen from the trail both above and below from the trail.
At Fort Harrison, a small population can be seen along the Harrison Trace Trail a short distance upslope from where Fall Creek Trail heads off to the left and Camp Creek Trail heads off to the right. As you near the top of the slope, look for it on the creek side of the trail. Along Fall Creek Trail, a small population can be seen on the creek side of the trail upslope from the last set of boardwalk structures.
At Mounds, a few plants can be seen in the southwestern part of the park along the river on Trail 5 near where Trail 1a heads up the slope. Look for it down low on the slope on the slope side of the trail, not the river side.
At Portland Arch Nature Preserve, this trillium can be seen along portions of the secondary trail on the property (not the main parking lot and trail that goes through the arch). They are visible from the trail in upland parts of that trail, not the lowlands.
Shades (including Pine Hills Nature Preserve), Spring Mill/Cave River Valley, and McCormick’s Creek SPs are all well-known for having populations here and there along various trails. There are also some in locations at Lieber/Cataract Falls SRAs.
Wherever you might go to discover these early spring bloomers, please remember to leave them where they are so that others may enjoy them and so that they can fulfil their roles in providing early spring pollen and nectar for emerging insects.