NOTE: This is not an exhaustive guide, and I am not an expert. Just wanting to compile what I've learned. Feel free to correct anything I've said here.

Dipsacus is a genus in the honeysuckle family, Caprifoliaceae. Both species in this guide are introduced to the US from Eurasia. They are two of three species present in the country. The third, D. sativus, is found only on the West Coast, whereas the two in this guide are more widespread.

Flowers

Flower color is not a good determiner of species. Generally, D. fullonum has lavender flowers and D. laciniatus has white, but this is not always the case. See below for some confusingly-colored specimens. Use this as an ID characteristic at your own risk.

D. laciniatus in pink | D. fullonum in white (Thank you @srall !)

Involucral bracts

These are the long, spindly things beneath the flower head. Their thickness, length, and prickle size and density can be good indicators of species.

D. fullonum:

• Narrow, delicate bracts that curve and twist, reaching the top of the flower head or above.
• Prickles are larger and widely spaced. Rarely absent. Occasionally with many smaller prickles between them.

D. laciniatus:

• Wide and short bracts that are more rigid and taper towards the tips.
• Prickles are smaller and usually evenly spaced but densely packed. Sometimes absent or nearly so.

D. fullonum bracts | D. laciniatus bracts

Leaves

There are a few leaf characteristics that can separate these species.

D. fullonum:

• Leaves are always unlobed.
• Leaf upper surface will have at least some prickles that give the appearance of pulled taffy.

D. laciniatus:

• Leaves are sometimes pinnatifid.
• Leaf upper surface lacking any prickles.

D. fullonum w/ unlobed leaves & raised bumps on leaf surface | D. laciniatus with unlobed leaves but lacking the raised bumps | D. laciniatus w/ some pinnatifid leaves & no raised bumps

These are the characteristics I've picked up so far. I'll probably be adding more as I find them. Thank you to @joedziewa for kindly providing most of this information.

Publicado el 31 de enero de 2024 a las 12:22 AM por bluebellprince