1. Flowers erect; tepals distinctly narrowed at the base to a slender claw; leaves up to 8 (–14) mm wide.
L. philadelphicum
1. Flowers nodding (fruit becoming erect); tepals narrowed gradually toward base, not clawed; widest leaves 8–35 mm wide.
2. Flowers pink or purple.
L. martagon
2. Flowers orange.
3. Tepals glabrous within; stem glabrous above; leaves mostly whorled.
L. michiganense
3. Tepals with pubescent strip basally within; stems with cobwebby pubescence, especially above; leaves alternate but crowded.
L. lancifolium
All species found in Lilium
Citation:
MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. January 21, 2020. https://michiganflora.net/genus.aspx?id=Lilium.