Horseweed (Conyza canadensis), Basil Rosette in Winter

Photo of Horseweed (Erigeron canadensis)

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Taken on Jan. 20, 2019

This photo shows a young horseweed (Conyza canadensis) plant growing as a basal rosette, mid-winter. Although this plant is often perceived as a summer annual because it is more visible and grows upright through most of the summer growing season, it often sprouts earlier and grows significantly during the cool season as well. During this time, it stays low to the ground, and it can look visually quite different from the adult plant, with leaves showing rounded lobes like pictured here.

On the day when this was taken, the temperature was well above freezing. The same plant looks quite different during sub-freezing temperatures. Compare with this photo of the same plant, taken the next day.