Carduus nutans (Musk thistle)
Image credit: Hermes RiveraIdentification tips
Tip #1: the name of the genus Carduus is from Latin to "thistlel-like plant". thistlel It is related to the word Cardonnacum ("a place of chardons or thistles"), which is the origin of Chardonnay,the name of the grape variety. The Latin nutans present participate in the nuto ("falter, give in").
Plant shape
2º Identification tip: this biennial plant begins its development in rosette of thorny leaves in the first year and the stems and purple flowers in the shape of a globe and appear in the second year, the plant produces up to 120,000 seeds that float to new places in down.
Leaves
3º Identification tip: the leaves the lobes of the lower leaves are divided into several smaller lobes and become smaller and less deeply lobed as they rise on the stem. There are numerous thorns along the wavy edges. The leaves have no stems, especially without hair,except in the main veins at the bottom, and may have a white tone on the edges.
Stem
4º Identification tip: the bases of the leaves extend down the stem, forming prickly "wings". The stems are many branched.
Flowers
5º Identification tip: the flowers have purple to pinkish color have large, layered bracts. The flowers are unique at the end of the branched stems.
Seeds
6º Identification tip: the seeds have long and white hairs, have brown coloration and oblong shape.
Seedlings - the terror of all
7º Identification tip: cotyledons are round and have smooth edges, while the first true leaves have the shape similar to cotyledon at the beginning of development and have the edge with thorns, these may have lighter coloration than the leaf.
Extra reference:
https://www.minnesotawildflowers.info/flower/nodding-thistle
https://www.wildflowers-and-weeds.com/weedsinfo/Carduus_nutans.htm
https://davesgarden.com/guides/articles/identifying-invasives-carduus-nutans-the-musk-thistle