Living plant collections play an important role in conserving plant biodiversity. Arboreta and botanic gardens collect and cultivate threatened tree species to learn about and safeguard important sources of tree genetic diversity. A rare variety of magnolia tree, Magnolia fraseri var. pyramidata (Fraser’s magnolia), is being grown and protected at The Morton Arboretum and other institutions.
Fraser’s magnolia is a small tree of conservation concern distributed predominantly throughout the plains along the Gulf Coast of the southeastern United States. It is threatened by a variety of destructive human activities, including clearing, disturbance, and development. In cultivation, Magnolia fraseri var. pyramidata is sparsely represented, and few trees have a documented wild origin. Trees in cultivation are almost exclusively of garden origin or their origin is unknown.
In 2016, only 14 arboreta or botanical gardens worldwide reported collections of the species to Botanic Gardens Conservation International (BGCI). Nine institutions that are members of the Plant Collections Network Magnolia Curatorial Group have the trees, but only one accession is of known wild origin. The variety is frequently commercially available from specialty nurseries, but is uncommon to rare in the horticulture industry at large.
In an effort to better understand the distribution of this species and increase documented holdings of this species in living collections, The Morton Arboretum partnered with Bartlett Tree Research Laboratories and Arboretum, Mercer Arboretum and Botanic Gardens (Texas), the University of Florida North Research and Education Center (Florida), and the Chicago Botanic Garden (Illinois) to scout populations, assess their health, and collect seed when present for propagation and distribution.
In August 2016, staff from these institutions collected 84 fruits and 507 seeds across 13 sites spanning seven counties, three states, and a linear distance of 545 miles (877 km). At each site, two specimens were also as herbarium vouchers to document the occurrence of the population. A total of 12 botanical institutions across the United States and Canada accessioned germplasm resulting from this project, aiding in effective distribution for ex-situ conservation purposes. A follow-up project was completed in 2019, involving additional collection from Alabama and Mississippi.