Born in Timaru, Mrs Eagle (87) first began painting New Zealand native plants in 1952 and about 50 years later achieved her goal of illustrating representatives of every native tree and shrub in the land.
Eagle's Complete Trees and Shrubs of New Zealand, a two-volume book compiling the fruits of her life's work, was published by Te Papa Press in 2007, and contained 806 painstakingly hand-painted plates.
She was ''a bit overwhelmed'' to be gaining an honorary doctorate at the university's 4pm ceremony, at the Regent Theatre, Dunedin, she said on Thursday.
It was ''wonderful to be recognised for all those years of hard work'', she said.
The book earned her the 2007 Montana Medal for Non-Fiction and the Booksellers Choice award. She has many other honours, including being appointed a Companion of the New Zealand Order of Merit in 2001 for services to botanical art.
Otago University vice-chancellor Prof Harlene Hayne praised Mrs Eagle's ''enormous contributions to botany and conservation'' and said it was fitting that the only university in New Zealand to retain a stand-alone botany department was honouring her in this way.
• Another Otago University graduation ceremony, also at the Regent Theatre, at 1pm tomorrow, will mark a milestone for dietetics education in New Zealand, when 19 graduands become the first in the country to graduate with a new two-year master's degree in dietetics.
''We're very excited about it,'' Otago University dietetics programme manager Dr Julie Weaver said. The Otago master of dietetics (MDiet) programme, introduced last year, prepared graduates to work as dietitians, and was a positive development for the university and the profession, officials said.
For future students, the two-year course replaces Otago's former 18-month-long postgraduate diploma programme in dietetics, which has run since 1993.
The first Otago MDiet graduates are a transitional group, having undertaken a year of PGD study before opting for a year-long research project last year, to complete the new degree.
