A Trio of Trillium

In honor of spring, here's some of the first wildflowers of the spring, on their way up to the light:

Prairie Trillium (Trillium recurvatum),
Van Patten Woods FP, Lake Co, IL 4/20/2014

These are Prairie Trillium (Trillium recurvatum), a rather odd name given that in Illinois they're found in open oak woodlands, rather than open prairies. These had just emerged, but by now they probably look more like this:

Prairie Trillium (Trillium recurvatum),
Van Patten Woods FP, Lake Co, IL 5/19/2003

If you think that one's pretty, take a look at this one from Pennsylvania:

Painted Trillium (Trillium undulatum),
Allegheny NF, Westmoreland Co, PA 5/19/2005

This is Painted Trillium (T. undulatum), a native of rich Appalachian hardwood forests.

And this one, from Ryerson Forest Preserve here in Lake County:

White Trillium (Trillium grandiflorum), Ryerson FP, Lake Co, IL 5/29/2003

This is White Trillium (T. grandiflorum).

White Trillium, being an exceptionally showy and abundant flower (in places, our forest preserves look carpeted in white from these guys), is noticed in it's absence. Here in Lake County, high deer populations have at times impacted Trillium populations. They tend not to disappear right away, but get progressively shorter over several years, until they're no longer able to flower. (1) Our forest preserves now practice population control methods to keep deer numbers down, and Trillium is doing just fine.

Another study shows that, while deer in large numbers are problematic, deer in smaller numbers can be helpful for White Trillium (and presumably for other trilliums as well). While most trillium seeds are dispersed by ants, deer are quite capable of doing so as well, and when they do disperse the seeds, they tend to do so at much greater distances than the ants manage. (2) This means that deer are an important determinant of the genetic population structure of the trillium -- not exactly the way I think of plant-herbivore interactions!

(1) Anderson, R. C. (1994). Height of white-flowered trillium (Trillium grandiflorum) as an index of deer browsing intensity. Ecological Applications, 4(1), 104-109.

(2) Vellend, M., Myers, J. A., Gardescu, S., & Marks, P. L. (2003). Dispersal of Trillium seeds by deer: implications for long-distance migration of forest herbs.Ecology, 84(4), 1067-1072.