Save Plants

Collecting and Conserving

This fall, The Arboretum at Flagstaff has been preparing packets of Packera franciscana propagules, a critically impaired or G1 listed endangered species found only on the San Francisco Peaks in northern Arizona, for seed banking at the National Center for Genetic Resources Preservation Laboratory in Fort Collins, Colorado. With funding provided by the USDA USFS Region 3 Forests Project and the Bureau of Land Management’s Seeds of Success Program, the Arboretum has collected eight species from 12 populations (totaling over 73,000 seeds!) that are important for conservation and research. Collecting trips have ranged from western Arizona, dipping into the Mohave Desert and north to the Arizona Strip, as well as to the top of Agassiz Peak just outside Flagstaff.

Living collections augment wild seed harvest for rare species research

Hawai’i has less than 1% of the land mass of the United States, yet contains almost half of the threatened and endangered plant species listed under the U.S. Endangered Species Act. In alignment with the Global Strategy for Plant Conservation, the Hawai’i Strategy for Plant Conservation, and the National Seed Strategy, we are investigating methods to preserve and protect Hawaiian species of conservation importance ex situ in the Seed Bank and Laboratory at the National Tropical Botanical Garden (NTBG). Our emphasis is determining seed, fern spore, and pollen storage behavior, longevity and aging kinetics, pathogen abatement, and seed dormancy and dormancy alleviation of native Hawaiian plant species of conservation importance.

One challenge that comes to mind around the fall harvest is collecting enough seed from our rare and imperiled species in order to conduct robust, meaningful research into seed conservation biology. One way we’ve been able to overcome this challenge for some species is by utilizing our Living Collections. For example, one of the species in the CPC National Collection in which we are tasked as being caretakers and that we are thus focusing conservation efforts, is Polyscias racemosa.

California Plant Rescue Initiative

In California, CPC members have come together as California Plant Rescue (CaPR), working to better conserve the immense botanical diversity of the state through seed collections. Working within an area that includes the California Floristic Province, home to over 6,000 plant species (not even including subtaxa!), over one third of which are endemic, there is an incredible amount of diversity in the state to be conserved. Such diversity can be daunting and requires collaboration and prioritization to make it achievable – and this is exactly what CaPR aims to do.

The need for prioritization was made clear in a recent study by staff at Rancho Santa Ana Botanic Garden (Meyer et al. 2014) which delved into the status of rare plant species held in regional seed banks. They found that a large proportion of rare plant taxa native to California represented in seed banks have formal legal protections – leaving behind the other taxa of conservation concern, such as those identified by NatureServe or the California Native Plant Society (CNPS) as rare and endangered. Thus, it is the goal of CaPR to collect 75% of the highest risk species recognized by CNPS.

Kew Foundation America Funds Seed Collections of Our Most Threatened Rare Plant Populations

In the areas of North America that were greatly impacted by major hurricanes in 2017, with the help of Kew Foundation America, CPC conservation officers valiantly made seed collections that will help save rare plants. In the southeast, Fairchild Tropical Botanic Garden researchers collected seeds of the globally rare and federally listed Linum arenicola and Linum carteri var. carteri. Because the plants are small, flower sporadically, produce few seeds, and there are few plants in the wild populations, repeated trips were required to gather adequate numbers of seed. In Texas, Mercer Arboretum botanist Anita Tiller collected Rayjacksonia aurea from a location highly threatened by development and Chloris texensis, which has been impacted by heavy grazing this year.

Imperiled Venus flytrap

Venus flytrap (Dionaea muscipula) is a carnivorous plant species endemic to 100 km landward radius centered near Wilmington, North Carolina, USA. This species is very well known to hobbyists and recognized throughout the world. However, in its native range, Venus flytrap is a conservation concern due to having a small number of robust protected populations and declines from threats such as fire suppression, land conversion, and poaching. There are 31 occurrences in North Carolina that are considered extirpated, or destroyed (NC Natural Heritage Program Database 2015) and 26 extirpated occurrences in South Carolina (Luken 2005). This represents a 17% decline in the number of occurrences range wide, and many of the remaining populations are small and unprotected. These recent declines have led to added legal protections for Venus flytrap (listed in NC, anti-poaching laws, assessment for federal protection). As part of ongoing conservation efforts, the North Carolina Botanical Garden is working to collect seeds of this imperiled plant. Collecting in the wet savannas that Venus flytrap calls home is hot work in June, but the botanical reward is well worth it.

Favorite Seed Germination Information References of CPC Conservation Officers

Michael Dosmann, The Arnold Arboretum of Harvard University: Dirr and Heuser’s manual on Woody plant propagation is a pretty good starting point for temperate woodies. The Reference Manual of Woody Plant Propagation: From Seed to Tissue Culture, Second Edition, by Michael A. Dirr,‎ Charles W. Heuser Jr.

Uli Lorimer, Brooklyn Botanic Garden: Native Plant Journal’s Propagation Database. There are loads of protocols to be found here as well as starting places for species lacking published protocols. The link is here.

Roger Gettig, The Holden Arboretum: Tallgrass Prairie Center Native Seed Production Manual; Seeds of Woody Plants in the United States, Forest Service, U.S. Department of Agriculture, Agriculture Handbook No. 450; and The New England Wild Flower Society Guide to Growing and Propagating Wildflowers of the United States and Canada, William Cullina.

Bart O’Brien, Regional Parks Botanic Garden:

• Everett, Percy C. 1957. A Summary of the Culture of California Native Plants at the Rancho Santa Ana Botanic Garden, 1927-1950. Rancho Santa Ana Botanic Garden, Claremont, CA. (Note: this is all the propagation information for the years when the garden was in Orange County.)
• Everett, Percy C. as edited by Bart O’Brien. 2012. A Second Summary of the Horticulture and Propagation of California Native Plants at the Rancho Santa Ana Botanic Garden, 1950-1970. Rancho Santa Ana Botanic Garden, Claremont CA. (Note: this covers the first 20 years of information at the Botanic Garden’s eastern Los Angeles County site in Claremont, CA. This publication is only available via FREE download here.
• Wall, Michael and John Macdonald. 2009. Processing Seeds of California Native Plants for Conservation, Storage, and Restoration. Rancho Santa Ana Botanic Garden, Claremont, CA. (Note: in addition to all sorts of great information about seeds and seed processing, this has incredible photographs of all the seeds covered individually by species.)

Andrea Kramer, Chicago Botanic Garden: In conjunction with the 2014 Baskin seed book, Seeds, Second Edition: Ecology, Biogeography, and Evolution of Dormancy and Germination, Charlie Willis created a great online database that allows you to search for species that the Baskins have worked with, and tells you their dormancy classification. If you are working with a new species, this can be a good starting point. You have to share your contact info to see it, but it is free. Log in here. And if nothing is known about the species, the Baskins published a paper in Native Plants Journal with easy-to-follow guidelines for a move-along experiment: Baskin, C. C., and J. M. Baskin. 2003. “When Breaking Seed Dormancy Is a Problem: Try a Move-along Experiment.” Native Plants Journal 4:17-21.