Descurainia incisa, July 28, 2020
Descurainia incana, July 30, 2020
Common & scientific name
Mountain tansymustard, Descurainia incisa & D. incana
Family
Mustard, Brassicaceae
Location
Roadside, 9,600
Fun, weird, helpful, or little known fact
Tansymustards try the patience of even the most careful botanists. They are all gangly, weedy-looking, tiny-yellow-flowered plants (leading to difficulty caring too much) that not only look alike but vary so much within their own species that you can’t count on certain attributes to distinguish them. As Flora of North America says about D. incisa:
“Plants glandular or eglandular, not canescent. Basal leaves: lateral lobes (3-)5-9 pairs, margins usually coarsely dentate to incised, rarely crenate or pinnatifid. Cauline leaves: lobes oblong to lanceolate, margins dentate to denticulate. Racemes glandular or eglandular. Fruiting pedicels ascending to divaricate, (3-)5-10(-12) mm. Fruits straight or curved inward.”
Clear as mud? So I’m calling the first photo Descurainia incisa, but honestly, your guess is as good as mine!
As for the second, I’m going with D. incana owing to its closely appressed siliques (the seed pods are resting tight up against the stem).