1. Heads with conspicuous rays clearly exceeding the involucre.
S. vernalis
1. Heads with rays minute (barely equalling involucre) or none.
2. Leaves and stems densely glandular pubescent; bracteoles at base of involucre (2–) 2.5–5.5 mm long.
S. viscosus
2. Leaves and stems glabrate to densely pubescent, but glandular hairs absent or sparse; bracteoles at base of involucre 0.9–2.6 mm long.
3. Rays present but minute, barely equalling involucral bracts; plant densely pubescent, with glandular hairs sometimes present but sparse; bracteoles at base of involucre and involucral bracts usually with greenish tips, rarely dark-tipped.
S. sylvaticus
3. Rays none; plant glabrate to somewhat tomentose, but without glandular-viscid hairs; bracteoles at base of involucre (at least some of them), and often involucral bracts greenish with conspicuous blackish tips.
S. vulgaris
All species found in Senecio
Citation:
MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. May 29, 2022. https://michiganflora.net/genus.aspx?id=Senecio.