Mary Katharine Brandegee (formerly Curran, née Layne; October 28, 1844 – April 3, 1920) was an American botanist known for her comprehensive studies of flora in California.

[2][3] The year after Curran died, Brandegee moved to San Francisco to attend medical school at the University of California at Berkeley, becoming the third woman to ever matriculate there.

She believed in evolution, unlike Kellogg and botanist colleague Edward Lee Greene, and she painstakingly researched botanical specimens to ensure that they had not previously been described, or were only varieties of known species.

As “acting editor” she provided botanists on the West Coast a way to publish their findings quickly instead of routing all new species naming through Asa Gray at Harvard, allowing for scientific independence.

[3] After the 1906 earthquake in San Francisco, the couple moved back and donated over 76,000 specimens from their personal collection to the University of California, Berkeley.

[5][6] Despite the fact that she was a diabetic who suffered regular attacks, as insulin treatment had yet to be invented, Brandegee continued to collect specimens in California until her death in 1920.