AUSTIN (KXAN) — Texas’ favorite wildflower is celebrating its anniversary Tuesday.

The 27th Texas Legislature adopted the bluebonnet as the official state flower on March 7, 1901, according to documents from the Texas State Historical Association. The bluebonnet — scientifically named Lupinus subcarnosus — earned its popular name due to its resemblance to a sunbonnet, per TSHA records.

On March 8, 1971, changes to the legislation incorporated L. texensis and “any other variety of bluebonnet not heretofore recorded.” TSHA noted a minimum of four other bluebonnet species grow in Texas:

  • L. havardii
  • L. concinnus
  • L. perennis
  • L. plattensis

In addition to the state flower, the Texas Legislature adopted in 1933 the state flower song “Bluebonnets,” written by Julia D. Booth and Lora C. Crockett.

As for why many bluebonnets are found along Texas highways, the Texas Highway Department executed a landscaping and beautification program in the 1930s. The flowers traditionally bloom in late March and early April, although weather variations can impact those bloom periods.