Navajo Spinach (Cleome Serrulata): Improving Seed Germination from Wild Populations Gathered across Native Lands of the Four Corners

Navajo Spinach (Cleome Serrulata): Improving Seed Germination from Wild Populations Gathered across Native Lands of the Four Corners

Summary

Native plants were commonly gathered and used by the Tribes of the Four Corners. One such plant is the Rocky Mountain Bee Plant, Cleome serrulata. This plant has several common names: stinkweed, stinking clover, skunk weed, and Navajo Spinach. Navajo Spinach is called “naá” by the Navajo, “túmi” by the Hopi, and “a’pilalu or ado:we” by the Zuni.  Historically, Navajo Spinach was a leafy vegetable in spring, plant tissue or seeds were used to color wool or paint pottery and baskets, and collected seeds were also ground for bread or eaten raw.

Navajo Spinach commonly grows on open rangelands, in disturbed soils around cultivated fields, and in sandy alluvial washes along stream beds. Wild populations of C. serrulata are scattered throughout the Four Corners. In 2016, we searched for wild populations of Cloeme from which we intended to collect seeds from for our germination studies. We also grew out seedlings from prior seed collection trips to increase seed stocks for additional study. 

Objectives/Performance Targets

1.  Collect Navajo Spinach from unique locations across the Navajo, Hopi and Zuni reservations.

Spinach seeds from Chinle, Arizona and Zuni, New Mexico were compared to commercially available seeds purchased from Great Basin Seed Company. Trips were taken to the Shonto, Chinle, and Keams Canyon areas of Northern Arizona and Southern Utah looking for additional Cleome populations. Dry weather conditions in 2016 had two effects on wild Cleome populations. First, while plants were found, wild plant population numbers were very low and quite scattered. Second, because of the hot, dry summer conditions, while plants flowered, pod set and pod seed numbers were very low. We did ID several new locations of plants and additional visits will be made to these sites in 2017 to collect seeds.

2.   Determine germination and growth requirements of Navajo Spinach seeds. 

Earlier studies show that germination is highest when seeds are chilled at 4C, less well at 10C and generally did not germinate at 20C. In January of 2017, we are repeating this experiment with a couple of changes. Treatments will include a 7C temperature (4, 7, 10, 20C). We will also double chill which will include exposing seeds to the various temperatures, returning them to room temperature, then placing them back into their respective cold temperatures for additional time. We are also evaluating various hormone treatments (GA 4, GA7 and GA4+7) along with the cold treatments. These are currently underway and data is just beginning to be collected. These studies will be repeated later in the spring.

3. Explore the Historical Practices, Cultural Uses, and Preservation Techniques of Navajo Spinach.

In the fall of 2016, research into the common practices, cultural uses and preservation techniques began as we attempt to document the role of Navajo Spinach in the cultures of the Four Corners region of the desert southwest.

Accomplishments/Milestones

In 2016, we grew out plants in Logan UT from seeds collected near Zuni NM and Chinle AZ. Plants were very vigorous, flowered profusely but did not really begin large seed sets until early-mid September due to the hot summer conditions of 2016. By October of 2016, we were able to collect more than 800 grams of seed from the Chinle plants and about 150 grams from the Zuni plants. These were dried, cleaned, sorted, and are now part of our test studies (described above). These extra seeds will significantly help us as we work through those parameters that contribute to Cleome seed dormancy. All seeds used in out studies are being evaluated for viability via tetrazolium testing. Commercial seeds are sold as viable but this does not indicate if they germinate. One outcome will be to report on the relationship between viability and germination.

Impacts and Contributions/Outcomes

No early impacts or outcomes to report. We are making good progress, have several studies underway, and will spend time in 2017 identifying new Cleome sites, collecting additional seeds and repeating our studies.