Possible noxious weed identification
From the photo's I am leaning towards the is a ditch willow or Coyote Willow and you are correct it is not a noxious weed in the state of Nevada.
I have provided you with two links with information about this will and the third from UC Davis goes into control measures and specific chemicals if you choose to control the plant in that means.
It may just be the age of growth. While willows that are well established around the Truckee Meadows are bloom, new sprouts at my home are at the same stage as yours.
Please let me know if you have any other questions.