Its comes as no surprise to many botanists that Tejon Ranch, and the Tehachapi Mountains in general, are a “gap” in distribution for many plant species. During the course of my research, one of my goals is to determine if this is a true “gap” in distribution (i.e. the plants simply do not occur on Tejon) or if this is the product of a lack of detailed botanical inventory. While there is still much work to be done, recent collections have begun to lend some insight into the answer to this question. Here is a quick tour of some of the highlights.
Brickellia nevinii (Nevin’s brickellbush)
Current distribution maps of this species show Tejon Ranch as a gap in distribution between known collections in the Western Transverse Ranges and the Southern Sierra Nevada. Late last summer, I made collections of Brickellia nevinii from two locations high on Blue Ridge closing a gap in distribution for this species.
Hulsea heterochroma (redray alpinegold)
This species has a distribution very similar to Brickellia nevinii, but a single collection in Little Oak Canyon closes the gap for this species. Dr. J. Mark Porter was fortunate to stumble upon this species while we were out collecting just a couple of weeks ago!
Eriogonum saxatile (rock buckwheat)
This species also has a similar distribution to Brickellia nevinii, known only from the Southern Sierra and Western Transverse Ranges. Within the Tehachapi Mountains it was previously known from a historical specimen with vague location information- maybe attributable to Tejon Ranch. This spring, however, I was able to make a collection of this species in Big Sycamore Canyon on the south slope of the Tehachapi Mountains, once again closing a distribution gap.
Eriogonum microthecum var. simpsonii (Simpson’s buckwheat)
This taxon represents a somewhat different case, as it was previously known primarily from the eastern Mojave Desert and the San Gabriel Mountains. The collection of this taxon from several locations on Tejon represents a range extension to the north and west by more than 100 miles!
Frasera neglecta (pine green-gentian)
Chris Winchell and I discovered this remarkable, CNPS Rank 4 species growing on carbonate rocks on an open ridge just last month. Previously this species was only known from the Western Transverse Ranges, so this represents an eastward extension of its range and a new ecoregional record.
These five examples are really just a sampling of the range extensions being found regularly on Tejon.
In addition, collections are enhancing what we know about the distribution of many plants previously known from a small number of locations on the ranch. For example, Syntrichopappus lemmonii (Lemmon’s syntrichopappus) is a rare plant included on Rank 4.3 of the CNPS Inventory. While this plant is known from the Western Transverse Ranges and South Coast Ranges it was previously known from only two locations in the Tehachapi Mountains. Recent fieldwork has now documented four additional locations on Tejon Ranch. This information will be shared with CNPS and the California Natural Diversity Database so that the distribution of this species can be mapped more accurately.
Stay tuned for more updates on the exciting botanical discoveries on Tejon Ranch!