The mystery of the Tejon Ranch Jewelflower (Streptanthus sp.)


IMG_0687The Tejon Ranch jewelflower, in flower

Last day of August, 2013

Streptanthus (also known as jewelflowers) is small genus in the mustard family (Brassicaceae) with its distribution centered in Western North America.  California is home to 35 out of 46 plants included in this group, 30 of which (85%) are considered rare by the California Native Plant Society.

On a late summer collecting trip I was driving along one of Tejon Ranch’s many dirt roads with Dr. Ed Kentner, David Varner, and Russell Kokx, when Ed spotted an interesting plant out of the corner of his eye.

IMG_0673Plants grow out of a granite outcrop.

I quickly stopped the truck and we hopped out to see what had piqued Ed’s interest. It was initially clear that the plant in question was a Streptanthus, and we went about the careful work of trying to determine which species it was.  First, we thought that the plant might be Streptanthus cordatus, but a comparison of characteristics determined it was probably not that species. Further efforts to determine its identification yielded no conclusions.  At that point we decided to make some specimen collections for deposit in an herbarium (essentially a museum housing plant specimens in an archival state) and take pictures of the plant and its habitat in order to make a final determination later.

That night we took turns under the microscope trying to identify the Tejon Ranch jewelflower to species with no success.  Back at the Rancho Santa Ana Botanic Garden Herbarium I compared my specimens to other species of Streptanthus known to occur in Southern California.  When that process yielded no conclusions to the plant’s identification I began to think that I may have made a collection of scientific significance.

IMG_0678Plants in fruit, seed wing size is very large for Streptanthus species

At that point I decided to send a specimen of the plant to Dr. Ihsan Al-Shehbaz of the Missouri Botanic Garden, a renowned expert on Streptanthus. Dr. Al-Shehbaz  (personal communication, 2013) concluded that the plant possesses a unique combination of characteristics, is quite possibly a species new to science, and warrants further study.

A couple months later, after comparing my plants on a molecular (using a region of nuclear DNA) and morphological basis with likely close relatives, I am nearly ready to conclude that the Streptanthus from Tejon Ranch  is, indeed, a new species.  This evidence is quite compelling when combined with knowledge of the geographical distribution of its close relatives (known based on molecular and morphological data),  Streptanthus bernardinus and Streptanthus campestris, both of which are rare species only known to occur in the San Gabriel Mountains and south.

Next summer, it will be quite exciting to explore potential habitat on Tejon Ranch and search for additional populations of this undescribed species. Once I find new populations of the Tejon Ranch jewelflower, I will take detailed measurements of the plants’ physical characteristics and leaf samples that can be used in a more comprehensive DNA-based analysis.  These vital steps are necessary to confirm conclusively that the Tejon Ranch jewelflower truly is a new species.


Pending the results of these analyses I plan on naming the Tejon Ranch jewelflower after my friend and mentor, Joe Medeiros. Joe is a long-time professor of botany at Sierra College, naturalist, and conservationist, who has inspired in countless individuals a desire to study and preserve California’s biodiversity. Look for an update on “Streptanthus medeirosii” late in 2014.




There are 3 comments left

  1. Pingback: Very callistum (beautiful) and Rare, the Tejon Buckwheat | Tejon /

  2. Ed /

    Cool blog Nick! But the corner of my eye was not involved! I was looking right at it, and from the fruits it was obviously a mustard, although I thought it was a Boechera until we got out of the truck and saw the flowers. What’s up with the weird Eriogonum nudum from that same site?

  3. Pingback: The curious case of the Tejon Heterotheca, or What is a herbarium specimen and why do they matter? | Tejon /

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