Sky's the limit: alpine plants on a Sierra Nevada sky island

Botany is addictive.  As a kid growing up near the western foothills of the Sierra Nevada mountain range, I took numerous summer camping trips to the forests where I loved trying to identify every kind of tree and wildflower I saw.  I would religiously consult the plant pictures and descriptions in my copy of T. Storer’s Sierra Nevada Natural History, the classic guide for anyone exploring California's most glamorous mountain range. 

Now as a graduate student in the research department at RSABG I am still fascinated with native plants. I am currently working on a floristic inventory of the Rock Creek drainage in Inyo National Forest on the eastern side of the Sierra Nevada, about 50 air miles southeast of Yosemite National Park.  On a topographic map the upper Rock Creek watershed appears as an eggplant-shaped hollow about 30 sq. miles in area, surrounded by steep granite ridges and peaks, many reaching 12000 feet and higher.  In the course of my research I have found there is little documentation about the biodiversity of the high mountain summits around Rock Creek, which are physically challenging to reach.

Rock Creek, Inyo NF

I'm inspired by the work of botanists whose insatiable curiosity has led them on searches for plants in wild remote places.  Long before before I was born, an accomplished botanist named John Thomas Howell made a challenging climb up a high mountain in the Rock Creek drainage that had no record of previous botanical exploration.  Howell—who earlier in his career had been the first botanist hired on staff at RSABG—described the flat-topped mountain as a “sky island” looming high above Rock Creek Lake.  It had no geographic name, so he called it Mono Mesa.  He originally saw it while on a botanical collecting trip through Mono Pass.  Howell climbed to the top of Mono Mesa in July 1946, collected representative samples of as many different plants as he could find, and shortly thereafter published a list of species.  He found 73 taxa, which he considered an impressive number for a high summit with ¼ sq. mile of land area.  Howell recounted his fascination with the barren yet beautiful landscape he described as a “velvet-textured monotony.”  He wrote that Mono Mesa was unusual, that unlike the surrounding jagged ridge tops it had never been glaciated, never changed by eroding effects of melting and moving ice.

Sky island: Mono Mesa's flat surface visible from the Mono Pass area

Sixty seven years later in summer 2013 I stood at our base camp at Summit Lake near the top of Mono Pass, impressed by the monumental view of Mono Mesa rising into the sky two miles to the north.  I contemplated my quest to resurvey the mesa, which had been many months in planning, preparation and no small measure of uncertainty.  Local folks in the Rock Creek valley had assured me that a day hike to the summit (12260 ft.) was very doable but there seemed no clear consensus on which route was best and no established trail to follow. 

We set out from camp the morning of July 12, a two-person team consisting of myself and RSABG colleague Travis Columbus.   It took us several hours to make our way cautiously along a narrow knife ridge of piled boulders leading up to the mesa edge and after many heart-pounding moments negotiating our way around gigantic boulders and sheer drop-offs we arrived at the summit in early afternoon.  I spent the remainder of the day collecting plant samples, recording GPS data and taking field notes as we surveyed the wide plateau.

Sky pilot (Polemonium eximium) is endemic to the Sierra Nevada

I was struck by the barren expanse of sandy rocky plain, practically devoid of trees and shrubs except for a few small, scraggly whitebark pines (Pinus albicaulis) clinging to the south rim.  A closer inspection revealed an assortment of small colorful plants with cushion- or mat-like growth forms, hugging the ground or sheltering under lichen-covered rocks as if to take refuge from the unforgiving alpine environment.  Plants have to be tough survivors up here.  Many species I happily observed still thriving on Mono Mesa decades after Howell documented them, including Davidson’s penstemon (Penstemon davidsonii), alpine gold (Hulsea algida), dwarf alpine Indian paintbrush (Castilleja nana) and sky pilot (Polemonium eximium): arguably the flashiest most charismatic alpine plant that only grows in the Sierra Nevada.

Alpine gold (Hulsea algida)

My curiosity to resurvey the mesa was especially keen because of the potential impacts of climate change. Warming temperatures are a significant threat to alpine plant communities especially on the highest summits where plants cannot disperse any higher to find cooler microclimates. Perhaps there are species still unknown to science persisting on Mono Mesa and atop other Sierra sky islands where the chance of discovering them is getting slimmer as the climate warms.  It was an unforgettable experience seeing the wonderful flora of Mono Mesa; hopefully my ongoing work to identify the plants I collected there will contribute to understanding life on these magnificent islands in the sky.

Upcoming field expedition for triple ribbed milkvetch

Astragalus tricarinatus on a cliff face near Mission Creek 

This coming spring the Conservation Program has an exciting new project that will be undertaken in some remote and underexplored sections of our California deserts to look for a federally endangered plant called Astragalus tricarinatus, or triple ribbed milkvetch as its known by its common name. This plant grows on an unusual geological substrate called “distressed granite” that is formed along the San Andreas Fault line where it bends and twists from its north/south trending direction to a more east to west trending direction in the Coachella Valley area. This Astragalus is a California endemic which means it is found nowhere else and is also considered a narrow endemic as its found in a relatively small area.

"distressed granite" outcroppings along the Pacific Coast Trail

The Conservation program had the great opportunity in the spring of 2011 to do surveys for Astragalus tricarinatus in the Whitewater and Mission Creek area where we visited many historic locations, found new undocumented populations, and collected a great deal of habitat information for this unusual plant, however a number of questions where left unanswered concerning some very old collections and literary references to this species being in other areas much more to the east. One of these curios historic records was left by a plant taxonomist named R. C. Barneby who was the leading expert on this genus in the 20th century. In his notes on Astragalus tricarinatus he wrote that it occurs in the Orocopia Mountains in Riverside County. While the Orocopia Mountains are geologically quite diverse, and in the path of the San Andreas Fault, they are still around 40 miles further east than the general area where Astragalus tricarinatus is found. There was no physical specimen of A. tricarinatus that we could locate from this range so all we have is Barnaby’s word that it grows there. While Barneby’s expert knowledge holds a lot of weight it is also important to have a physical specimen in a herbarium that can be visited and studied and this is one of the main goals for this project we will be undertaking, to locate A. tricarinatus in the Orocopias, asses population status and population numbers and collect as much information on this endangered plant that we possibly can.

Spencer's voucher from Chuckwalla Mtns (Harvard image)

One herbarium specimen we do have to go on, that has also been one of question, is a collection from 1921 from Mary Spencer that was apparently collected even further east in the Chuckwalla Mountains. The Chuckwalla Mountains are pretty far from the San Andreas Fault, and while they are made up of granite they don’t appear to have the “distressed granite” that Astragalus tricarinatus prefers. So this specimen brings up many more questions: can A . tricarinatus grow on other geological substrates besides “distressed granite”? There has been a good deal of visitation by botanists to this range in the past 100 years, so is it possible that at one time A. tricarinatus did occur here but no longer does? Was this perhaps a “waif” population? And while Mary Spencer wrote on her collection label “Chuckwalla Mountains” could she have been referring to a larger area that would also include the Orocopia Mountains? The only thing we know for sure right now is that the plant collected by Mary Spencer is definitely A. tricarinatus, we have this very important herbarium record that we can visit and reference, but the big question is: where exactly did she collect it? Perhaps she found the same population that R. C. Barnaby writes of. These are all questions we are hoping to answer this coming spring.

Regenerating a Rare Sunflower

In my mind, the sunflower may be the most iconic American plant. It’s a plant of summer, a plant of fall, a plant chewed on the ball field (and a healthier one than the other plant commonly chewed on the diamond, Nicotiana tabacum). My earliest gardening memories are of a sunflower; of planting a seed in a Dixie cup with my preschool class and watching it grow in my parent’s garden till it towered over my head.  It was fitting that one of the first plants that I worked with at Rancho Santa Ana Botanic Garden (RSABG) was a sunflower.

Flowers of Helianthus inexpectatus

The seed bank at RSABG is always adding new seeds to its collection. Each of these new seed collections must be tested to make sure that the seeds are alive. There are several ways to test whether or not a seed is alive.  The method that we use for most of our seed collections is germination testing. This process is fairly straightforward. We take a small sample of seeds, and germinate them under very specific and controlled conditions. By looking at the ratio of seeds which sprout compared to the total amount of seeds which were sown and dissecting and making observation about any ungerminated seeds we can get a good estimate of the percentage of viable (living) seeds in a collection. On my first day at RSA, an assortment of interesting seeds was ready and waiting to be tested. One of these was a sunflower, and a rather unusual one…

The Newhall Ranch Sunflower (Helianthus inexpectatus) wasn’t formally described until 2010, when David Keil and Mark Elvin published a description in  Aliso, the scientific journal of RSABG. Before the description, there was some confusion about what this plant actually was. It was found at Newhall Ranch, an interesting and controversial piece of land just south of the grapevine along the I-5. When they were discovered, there was some confusion about the taxonomic identity of these plants. Based on pollen size, chromosome counts that differed from closely related species and other factors, the plants were described as an entirely new sunflower.

Since the seeds came from such an unusual plant, we used a very small sample to test their viability. 30 seeds were sown, 17 of which germinated. This gave us our baseline of viability for the collection, and the added bonus of 17 tiny plants. In some of our tests, the plants which are produced inevitably end up being discarded, often in a spectacular display of fungal attack, but with these unusual seeds we knew that we wanted to grow them on. The plants were grown in small two inch pots for several weeks and were tended to with care by our talented nursery staff. Once they were large enough, we transferred them to raised beds, where we could grow them to maturity.

Seeds of Helianthus inexpectatus

Seed regeneration, also known as seed bulking, is the process of taking a small amount of seeds, growing plants from them, and collecting and storing the seed that those plants produce. The 17 plants that were produced during germination testing were used for this purpose. After a long summer of frequent watering and the occasional threat of insect attack, the plants flowered and began to set seed. We harvested seed over the course of approximately one month, collecting mature flower heads and storing them in a dry area in paper bags. Many of the seeds were found to be unfilled and non viable, but some were healthy and normal. Altogether we were able to harvest more than 2,500 viable and healthy seeds from the 30 seeds that we started with in our germination test. The seeds that we produced will be stored at the RSABG seed bank, and will be available to the botanical researchers and conservationists. 

Susanna Bixby Bryant, the founder of RSABG, envisioned an organization that would “…replenish the depleted supply of some of the states rarest plants.” Many years after she wrote those words, it is an honor to be continuing this work, methodically collecting, storing, growing, and regenerating our states rarest plants.

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!

Why plant names change

This article written by Lucinda McDade was originally posted in Oak Notes, the newsletter of the Volunteers of RSABG. Because it answers questions that come up frequently, we thought we'd share it here too.

Why do those annoying scientists keep changing the names of plants? In this month’s column, I 
am going to attempt to convince you that name changes reflect progress and should be embraced with enthusiasm owing to the information that they convey. First, though, let me agree: names changes are annoying. I rather like Senegalia greggii (formerly Acacia greggii), and I am warming up to Erythranthe (for the sweet little monkeyflowers that grad student/conservation botanist Naomi Fraga studies), but Acmispon and Hosackia (both formerly Lotus) just don’t roll off the tongue smoothly and still leave me a little cold. Nonetheless, I too must  learn to say Acmispon and Hosackia with grace. 

So why do scientists keep changing plants’ names? The answer is actually pretty simple: because we have learned more about the “ family tree” (i.e., evolutionary relationships) of the plants in question and seek to reflect that knowledge in our scientific naming of the plants. We could of course keep knowledge about relationships and names separate, but biologists have almost unanimously agreed that we should use the scientific names of organisms to convey information about relationships. Interestingly, by following a few simple rules in assigning scientific names to organisms, we can do this quite readily. Here we have the culprit: because we are directed to depict patterns of evolutionary relationship when naming organisms, names sometimes must change as our knowledge of relationships grows. Thus the fact that the names of our monkeyflowers have changed to Erythranthe and Diplacus alerts us  that modern work to understand the evolutionary  history of the genus Mimulus has revealed that all plants with monkeyflower-like flowers are not each other’s closest relatives. The evolutionary tree for Phrymaceae indicates that the plants that have been referred to as Mimulus occur in three different branches of the tree. More closely related to each of these evolutionarily independent monkeyflowers are plants that have never been referred to as Mimulus and that have flowers that are quite different from what we expect monkeyflowers to look like.

When advancing knowledge demands name changes, in order to avoid total chaos, we follow the rule that the scientific name stays with the type species. Think of the type species as providing a sign post for where the genus name belongs. In this case, the type species, M. ringens, occurs in eastern North America and species on that branch of the evolutionary tree retain the name Mimulus. The two branches where the western monkeyflowers are placed are now referred to as Diplacus (the woody perennial subshrubs like D. aurantiacus) and Erythranthe, which are the diminutive annuals that Naomi studies. It is notable that both of these genus names far pre-date the phylogenetic results that are now our basis for using them again: our predecessors had an inkling that these groups existed! Knowledge of the patterns of relationship among these plants tells us that the suite of floral traits that makes a monkeyflower look like a monkeyflower may well have evolved multiple times rather than just once. 

The story of California fuschia, formerly referred to as Zauschneria, is the converse of the monkeyflower story. Here, the results of modern evolutionary studies show us that the handful of species that had been called Zauschneria are just a small twig on the large phylogenetic tree that is the genus Epilobium. Fixing this problem of mismatch between names and evolutionary patterns could involve breaking Epilobium (with as many as 200 species) into a large number of genera, but it would be challenging to point to traits that would let us tell one from the 3 other, which is almost as annoying for users of taxonomic names as is changing names! Also note that this path would create a lot of new genus names. The alternative path has been chosen: Zauschneria has been moved into Epilobium. This change should  lead you to understand that the remarkable large red, hummingbird-pollinated flowers of Epilobium canum likely evolved from less charismatic flowers that mark most species of Epilobium. This is interesting and makes us want to know more 
about the evolutionary history of these plants.

The take home message is that change is annoying, but learning is good (as I know that the many of you who are teachers will agree!), and the fact that knowledge is advancing rapidly is great. I am convinced that it is well worth our while to learn these new names because they instruct us about evolutionary relationships of the plants we love. The other simple fact is that for people just starting to learn plant names now and for all those who come after them, new names are not in fact “new” but are just names!

 I am going to change gears now and fill in a bit of the background on the science that is behind the discoveries that are behind these name changes. If this is too much information for you, feel free to skim/skip. Also, let me know whether you like or do not like this sort of information. That will help me make these columns useful and interesting to you. These are very exciting times in the branch of  biology—systematics—that has responsibility for documenting and understanding biodiversity—the living organisms that share planet Earth with us. Since the time of Darwin, it has been understood that our goal is to unravel evolutionary relationships. Organisms are related to each other to different degrees, owing to evolutionary patterns—to recency of shared ancestry. Thus, just as you and your siblings are more closely related to each other than to any other human beings owing to sharing the same parents (i.e., very recent common ancestors!), so oaks are more closely related to other oaks than to ashes or alders because they stem from a common ancestor that lived much more recently than did the ancestor shared by oaks, ashes and alders. 

Despite this widespread agreement that we seek to unravel evolutionary relationships, until about 50 years ago, it was not clear how to discover these patterns of relatedness—how to organize our observations of similarities and differences between organisms to reveal degrees of common ancestry. A very clever German entomologist, Willi Hennig, figured it out in the 1960s and this sparked a burst of energy in systematics. Next, during the late 1980s and into the 1990s saw the development of methods to gather DNA sequences (yes, the exact order of the Cs, Gs, Ts, and As in genes—happy to show you in our molecular lab how this works!). This provided incredibly powerful information for deducing relationships. By the way, both the principle contributed by Hennig and the DNA methods are elegant to the point of simplicity—the sort of thing that, once you understand, you  feel that you could and should have figured out on your own! A final ingredient “stirred in” over the last couple of decades has been advances in analytical methods. The field has recruited many extremely talented mathematicians who are devising analytical methods that follow Hennig’s principle while taking advantage of the huge amounts of data that can now be amassed in the molecular lab. That fertile mix has yielded a revolution in our understanding of how organisms are related to each other. 

Those of us contributing to the revolution undertake research that yields tree-like, branching diagrams that depict patterns of relationships among the organisms that we study. As noted above, by following some simple rules when we assign scientific names to organisms based on relatedness, we can convey information about relatedness in our biological classifications. The most important of these rules is that any taxon (e.g., family, genus) must include all of the descendants of a common ancestor. These are very exciting times in the branch of biology—systematics—that has responsibility for documenting and understanding biodiversity—the living organisms that share planet Earth with us. only the descendants of that common ancestor. The knowledge that Zauschneria is a twig on the tree that is Epilobium can be restated more “formally” as: Zauschneria shares a common ancestor with some species of Epilobium (those on the same branch of the Epilobium tree) more recently than any common ancestor that ALL Epilobium share. This  means that we cannot recognize both Epilobium and Zauschneria because this would break the “all  descendants” rule, and we will not be able to  understand the relatedness of these plants from the classification. I hope that makes sense – it is actually easier to “get” from a diagram and I’d be happy to go over that with any of you who might be interested. 

 One more point before I leave this topic: because the name changes that we are now experiencing are based on the above described three major advances in our field, there is every reason to believe that they will achieve a level of stability that we have not had in the past. Although we can’t promise that this round of name changes will be the last, there is every reason to believe that they are a major step toward achieving stability