The Vascular Flora of the Yaqui Pass Area, Anza-Borrego Desert State Park
Introduction
Species Checklist
Introduction Pinyon / Yaqui Ridge is the prominent ridge seen south and southwest from the Borrego Valley that forms the southern boundary of Borrego Valley. The Ridge has been raised along faults on its north and south side, creating very steep slopes for much of its north and south slopes.
The Ridge is cut near its eastern end at Yaqui Pass, which is traversed by Highway S3, the Yaqui Pass Road, which is renamed Borrego Springs Road when it enters the Borrego Valley. The portion of the Ridge east of Yaqui Pass has been named Yaqui Ridge.
The Yaqui Pass area is shown in Fig. 1, along with the routes we have surveyed, and the area searched for vouchers. We define the Yaqui Pass area to be that area of Pinyon / Yaqui Ridge which is most easily accessed from Highway S3, excluding the area of San Felipe Creek, which has a very different flora. The southern boundary is therefore fairly well defined, but the northern boundary is nebulous, where Pinyon / Yaqui Ridge grades into the alluvial slopes of Yaqui Meadows / Borrego Valley.
Fig. 1. The Yaqui Pass area. The area searched for vouchers is outlined by the black rectangle. Five surveys have been done in this area, two in the area north of Yaqui Pass from S3 to a major drainage to the west, two along the ridge west of Yaqui Pass, and one along the ridge area east of Yaqui Pass, labeled by the dates of the surveys. The unlabeled red surveys at upper left are part of the Glorietta Canyon flora.
We first became interested in this area when Charlie Jones told James Dillane about the Scutellaria mexicana (=Salazaria mexicana) he had confirmed here on 28 April 2009 with Charles L. Bennett, after Charlie had spotted them blooming a few years previously at this location. Pictures of these plants are here. The location of these plants is shown in Fig. 1 at the far left, at the location of the flag with the hard-to-read reduced label of Salazaria.
This checklist is only a start at a flora of Yaqui Pass, since we have done only five surveys here, sampling only a small fraction of the total area. Also, our surveys were never done in a good rainfall year.
The surveys done so far are:
- Three surveys on the ridge west of Yaqui Pass. The number of plants from the union of those three surveys are given in the column Rdg in the checklist below.
- A mostly-hike on 3 December 2010 of 3.3 miles of the ridge west of Yaqui Pass, by Tom Chester, James Dillane, and Charlie Jones, from 1700 feet to 3367 feet. This trip had the specific goal of vouchering the Scutellaria mexicana (=Salazaria mexicana) discovered by Charlie Jones there a few years earlier. Only 27 species were recorded on that trip: those that were in bloom, associates at the Salazaria voucher location, and a few other species found only on the plateau area that contained the Salazaria. After the trip, additional species were recorded from memory, and abundance estimates were made, resulting in a total of 65 species.
In 2014, we have memories of Oligomeris linifolia from this survey, but since it wasn't recorded in a timely manner, and human memories sometimes confuse different trips years later, we haven't placed it in the checklist.
- A survey on 5 December 2014 of 1.6 miles of that ridge, by Tom Chester, Adrienne Ballwey, Jim Roberts and Jeff Field, from 1700 feet elevation to 2880 feet. This survey found 56 species. A somewhat different route was taken on the way back from the farthest point reached along the ridge, for 1.05 miles, but no additional species were found.
- A survey on 23 November 2019 of 1.0 miles of that ridge, by Tom Chester, Nancy Accola, Don Rideout, and for part of the time, Joe Woods, from 1750 feet elevation to 2545 feet.
- Two surveys in the area north of Yaqui Pass, extending from Highway S3 to a major drainage on the west. The number of plants from the sum of those two surveys are given in the column Cyn (for Canyon) in the checklist below
- A survey on 15 February 2013 reaching 1.75 miles of the area west of Highway S3, beginning at S3 1.3 miles north of Yaqui Pass, just south of the small hill Ship on the topo map, by Tom Chester and Adrienne Ballwey. The survey reached a major drainage to the west, and surveyed up that canyon for 0.13 mile. A total of 2.5 unique miles were covered, by taking a different route for part of the way back. A total of 77 species were found.
- A survey on 10 March 2013 of 0.8 miles of that major drainage, and 0.8 miles of the minor drainage to its immediate east that joins the major drainage at the lower end of this survey, by Tom Chester, Kate Harper and Lance Holmberg. A total of 2.4 additional miles were surveyed, with an additional 35 species found, for a total of 112 species in this area.
- One survey in the area east of Yaqui Pass, including the Bill Kenyon Overlook Trail (see San Diego Reader Canyoneers page and Hikespeak.com page), part of Highway S3 and the wash north from Yaqui Pass, on 23 December 2014, by Tom Chester, Keir Morse, and James Dillane. That survey covered 4.2 miles, finding a total of 75 species.
A total of 141 taxa were found in the union of all five surveys. (Numbers not updated from additional surveys after 2014.)
Vouchers from the Yaqui Pass area were obtained from a search on 16 February 2013. The Consortium records were searched for vouchers with coordinates between 33.14 and 33.17° N. Latitude, and -116.37 and -116.31 E. Longitude. An additional search was made for vouchers with Yaqui Pass in their locality. A review of the localities resulted in eliminating 14 vouchers as not being in the target area, leaving 117 vouchers, of 67 unique taxa.
This voucher search box is smaller than the area we define as the Yaqui Pass Area, but there were no vouchers with coordinates in the area of Pinyon / Yaqui Ridge to the west of this search box, and the only vouchers to the north of the search box were well away from the Yaqui Pass area, in the transition to the alluvial plain.
Species found in those vouchers to the north, that are not present in this Yaqui Pass Area checklist, are:
- Calycoseris wrightii
- Chaenactis stevioides
- Cryptantha angustifolia
- Logfia depressa
- Malacothrix glabrata
- Nemacladus rubescens
- Psathyrotes ramosissima
The combined checklist from surveys and vouchers contains 156 taxa. Of those 156 taxa, 89 were found only from our surveys; 52 were found both in our surveys and in vouchers; and 15 were found only from vouchers. (Numbers not updated from additional surveys after 2014.)
For photographs of 400 observations from this area as of 26 November 2019, see the Inaturalist observations from this area.
For a hike description from Yaqui Pass to the Sheep Guzzler on the ridge west of Yaqui Pass, along with many photographs of this area, see Fred Melgert and Carla Hoegen's Yaqui Ridge Peak.
Species Checklist See:
- Notes on the Scientific Names Used At This Site and
- Information about the links from the Scientific Name and Common Name.
The column with header Famil gives the first five letters of the plant family name. See Plant Family Abbreviations.
An asterisk before the common name indicates a non-native species.
The column with label BW links to the photo gallery page for each species at Fred Melgert and Carla Hoegen's BorregoWildflowers site.
The column #V gives the number of vouchers found in this area.
The columns #Plants gives a minimum estimate of the number of plants from the field surveys in the separate areas surveyed, up to a maximum of 99 plants, for species for which abundances were estimated. The main intent of this estimate is to indicate the species for which we found very few plants.
The column RdgW is for the three surveys along the ridge west of Yaqui Pass, and the column RdgE is for the single survey along the ridge east of Yaqui Pass, including part of the road and wash north from Yaqui Pass. Note that no survey has been done at prime time in either of these areas, and thus these columns are missing most spring annuals and perennials.
The column Cyn (for Canyon) is for the area north of Yaqui Pass that included a major drainage to the west.
It is possible that Oligomeris linifolia should be added to the checklist; we'll search for this in future surveys.
See also the neighboring Glorietta Canyon flora.
Version for printing, without lines and other text on this page: html (4 pages) or pdf Clickbook booklet (1 double-sided page). (See printing instructions for an explanation of these options)
Voucher data provided by the participants of the Consortium of California Herbaria (ucjeps.berkeley.edu/consortium/).
We thank Charlie Jones for telling us about the Salazaria here, and for providing a picture to give the Calochortus determination. We thank Joe Woods for his help with part of the 23 November 2019 survey.
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Copyright © 2014-2019 by Tom Chester, Adrienne Ballwey, Keir Morse, James Dillane, Jim Roberts, Jeff Field, Kate Harper, Nancy Accola, and Don Rideout.
Permission is freely granted to reproduce any or all of this page as long as credit is given to us at this source:
http://tchester.org/bd/flora/yaqui_pass_area.html
Comments and feedback: Tom Chester
Updated 27 November 2019.