Field Pennycress
Thlaspi arvense
Mustard family (Brassicaceae)
A common weedy mustard from Europe, Field Pennycress has spread across the United States. The common name arises from the distinctive penny-like round . Field Pennycress contains mustard oil (isothiocyanate), which can poison livestock. The plant's unpleasant smell when crushed gives rise to one of its other common names, "Stinkweed."
lobe -- Being divided by clefts.
An annual plant is a plant that completes its life cycle, from germination to the production of seed, within one year, and then dies.
cross -- To make something interbreed. The act of hybridization.
Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom.
fruit -- any seed-bearing structure in flowering plants. It is formed from the ovary after flowering.
A clasping leaf suroundes part of all of the stem.