The Holden Arboretum, in Kirtland, Ohio, is one of the largest arboreta and botanical gardens in the United States, with more than , including devoted to collections and gardens. Diverse natural areas and ecologically sensitive habitats make up the rest of the holdings. Holden's collections includes 9,400 different kinds of woody plants, representing 79 plant families. Specializing in the woody plants that can be grown in the climate of northern Ohio, Holden has a number of specimens obtained during wilderness collection trips, particularly to China and Korea near the 40th parallel, areas with a similar climate to Northeast Ohio. Many Trees like Dawn Redwoods are planted there. Holden is home to two National Natural Landmarks, accessed by guided hikes, and is a Midwest representative for The Center for Plant Conservation. Special gardens include the Myrtle S. Holden Wildflower Garden, the Helen S. Layer Rhododendron Garden, and the Arlene and Arthur Holden Jr. Butterfly Garden. The Holden Arboretum also features extensive Crabapple, Lilac, Viburnum and Conifer Collections. History The arboretum is named for Albert Fairchild Holden, a mining engineer and executive, who had considered making Harvard University's Arnold Arboretum his beneficiary. However, his sister, Roberta Holden Bole, convinced him that Cleveland deserved its own arboretum. Thus Mr. Holden established an arboretum in memory of his deceased daughter, Elizabeth Davis Holden. When he died in 1913, at age 46, Mr. Holden left a trust agreement in which he provided that funds be designated for an arboretum. After a study of possible sites, Roberta Holden Bole and her husband, Benjamin P. Bole, donated 100 acres (40 ha) in Kirtland Township. In 1931, the Cuyahoga County Court of Common Pleas approved establishment of The Holden Arboretum. In December 1988, 75 years after Albert Fairchild Holden's original bequest, the Holden Trust began to benefit the arboretum as he and so many others had envisioned. His permanent endowment, together with the gifts of other contributors and supporters, make possible the development of a truly first-class arboretum. The geographic area that Holden has property within comprises two counties, Lake and Geauga, and 5 townships and municipalities. Major collections The Display Garden maintains a landscaped array of Lilacs, Viburnums, bulbs and companion plantings. The Helen S. Layer Rhododendron Garden contains heaths and vernal witch-hazels in March, through to the fall heathers and native witch-hazels in October and November, with over 1,200 rhododendron plants and over 100 mountain laurel