The Polly Hill Arboretum will be offering two classes for those interested in learning more about the scientific study of plants.

On Thursday, Sept. 30 from 1 to 4 p.m., Susan Hardy Brown, Arnold Arboretum curatorial assistant, will lead a hands-on workshop on the basic skills necessary for creating herbariumspecimens. Collecting procedures for both woody and herbaceous plant material and techniques for mounting these after they have dried will be covered. Those receiving this training will be eligible to work with future herbarium specimens at theArboretum. Preregistration r equired.

On Friday and Saturday, Oct. 1 and 2 Polly Hill research associate Melissa Dow Cullina will lead an intensive two-day workshop on the identification of Island goldenrod species. Students will study the many goldenrods (solidago and euthamia) of Martha’s Vineyard. On day one, Ms. Cullina will give a presentation on the 19 species reported for the Island, discussing their various features, abundance and habitat, and introduce students to terminology and morphology specific to goldenrods using photographs and specimens. Day two the class will go afield to practice identification in the wild using field guides and manuals. Space is limited and preregistration is required at 508-693-9426. Class is from 9 a.m. to 3 p.m.; bring a brown bag lunch. Cost is $120, or $100 for arboretum members and $80 for professionals associated with Island land management or conservation.