Yellow Sweetclover (Melilotus officinalis) can be found growing here in Tucson, but it is much more common in our local mountains.

I found this Yellow Sweetclover growing near the water in Sabino Canyon, and the seeds for it may have been washed down from the mountains. The plant was doing quite well here at this lower elevation though and was 4 feet (1.2 m) tall.

This non-native weed is very similar to the also non-native Annual Yellow Sweetclover (Melilotus indicus), but Yellow Sweetclover is taller and has larger, more attractive flowers. The smaller M. indicus is far more common here in Tucson than M. officinalis, perhaps because it needs less water.

Bees make delicious clover honey from Yellow Sweetclover flowers, which is why this Eurasian bee plant has been so widely planted. Because of this, it has become naturalized in many areas and can be considered an invasive weed.