It pops up everywhere out here. We find it along the roadsides, creeksides, barn sides, and even on the rocks where a bit of dirt might gather. It's not fussy. It's tough and grows in the most unlikely places.
2000 years ago, Dioscorides recommended the plant as a curative for lung problems - coughs, colds and bronchitis. It has been included in many official and national formularies.
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The flowering stalk gets about 5 feet tall and has small yellow flowers along it. Rumor has it that the flowers are good as a natural dye. I've never used it, since collecting them would be tedious and it would take a long time to get enough to dye much at all.