Seed Collecting in the Mojave and Sonoran Deserts

Deidre collecting Joshua tree (Yucca brevifolia) seeds north of Barstow, August 2013

Hello, my name is Deidre and I started working at the Rancho Santa Ana Botanic Garden (RSABG) as a Seeds of Success Intern in August, 2013. I am originally from the Twin Cities, Minnesota, and did my undergraduate work at the University of Wisconsin- Madison.  While I have some field experience out west in Montana and New Mexico, working on Seeds of Success in California has been a bounty of new plants, habitats and culture to experience. It is amazing how much public land remains in Southern California, especially in the Mojave and Sonoran deserts. Though I have moved to one of the most populated areas of the country, I find myself in areas where I don’t see another soul for most of the day. I will give an overview of the Seeds of Success project, a typical work day, and some of this year’s highlights.
  

Seeds of Success is a national program set forth by the Bureau of Management (BLM) that aims to collect, conserve, and develop native plant materials for stabilizing, rehabilitating, and restoring lands in the United States.  RSABG receives funding from the BLM as a partner to combine seed collecting efforts in Southern California. For 2013, our team made a total of 67 collections from 31 different species native to California.  A typical collection includes a minimum of 10,000 seeds, a voucher of the plant, photos of the plant, seed, and site, and data describing the location, habitat, soil, and associated species. 

Manybristle chinchweed (Pectis papposa) near Algodones Sand Dunes, October 2013

So how do we find these native plant populations? First, we do some research at the garden taking precipitation, herbarium records, and bloom periods into account. We may plan a trip based on one or all of these three factors; rain is often the key to finding blooming plants in the desert, even outside of normal bloom periods. Since our collecting regime is so large, we rarely run out of places to check for populations and many stops are added on the fly if we spot the telltale sign of water in the desert: green creosote bush (Larrea tridentata).  Once we find a population that has at least 50 plants that are flowering and appear they will likely make at least 10,000 viable seeds, we take photos and voucher a few plants for herbarium records. About a month after full flowering, we will return to collect seeds. We test for ripeness with a cut test to split the seed and make sure the inside is filled, firm, healthy.

Some 2013 collecting highlights:

Acton’s brittlebrush (Encelia actoni)

The first collection I made upon arriving to California was of the Joshua tree (Yucca brevifolia) north of Barstow. It was like walking from one spiky desert piñata to another as we used sticks and rocks to knock the fruits off the inflorescence and catch them or quickly gather them off the floor.

Manybristle chinchweed (Pectis papposa) was the “yellow carpet” of Mojave and Sonoran desert this fall. The late summer rains allowed for the hot water needed to germinate generally thousands of chinchweed seeds in an area. It has a very distinct smell that was very useful for identification even before the bright yellow flowers were open.

  Parish’s goldeneye (Bahiopsis parishii)

Final collection of the season, (this December!), was in Ruby Canyon of the Bighorn Mountain Wilderness area. Acton’s brittlebrush (Encelia actoni) and Parish’s goldeneye (Bahiopsis parishii) were that last two species for 2013 in a part of the high Mojave that is still surprisingly colorful for this time in the year.

This year, I have especially enjoyed working outside, making seed collections at seemingly desolate sites upon first glance, and appreciating parts of the desert that no one may have ever appreciated. I am thankful for such a lovely field season and opportunity to conserve the precious native plants of Southern California. Check back for more collecting news in the spring!