Flora of southeast Granite Mountain, Anza-Borrego Desert State Park
Introduction
Granite Mountain is a fairly-well-isolated large mountain that towers over the San Felipe Valley to the north, and Mason Valley to the south. It spans 6.5 miles east-west, and 4.0 miles north-south. It is on the immediate east of the Laguna Escarpment, southwest of Julian and Banner, and shares many montane species with those neighbors on its western side. It is on the immediate west of Shelter / Earthquake / Blair Valley, and shares many desert species with those neighbors on its eastern side.
We have long wanted to do a flora of the different sides of Granite Mountain, to document how the flora changes with cardinal direction. The checklist here is a first attempt to produce a flora of the southeast side of Granite Mountain. The flora is almost certain to be quite incomplete since much of Granite Mountain is very steep and difficult to access.
The southeast side has a north-south extent of 2.7 miles, and an east-west extent of 4.0 miles. It reaches its lowest elevation of 2300 feet at the junction of Box Canyon and Vallecito Wash on its southeasternmost end. The elevation increases to 2600 feet on its easternmost extent at the north end of Blair Valley; and to 2800 feet on its southern end, immediately south of the peak, in Rodriguez Canyon. The peak of Granite Mountain is at 5633 feet.
Fig. 1 shows a Google Earth view of Granite Mountain from the southeast.
Fig. 1. A Google Earth view of Granite Mountain from the southeast. The blue track is the route surveyed in Hornblende Canyon on 3 March 2014. Click on the picture to see a larger area.
This list comes from:
- vouchers from the southeast side of Granite Mountain, obtained from a search on 5 March 2014 of the Consortium of California Herbaria using coordinates and localities.
The top collector by far was Larry Hendrickson, whose name was on 289 of the 730 vouchers, 40% of the total. Philip Munz was next, with his name on 92 vouchers, 13% of the total. Carl Epling (70), Frank Gander (48) and Victor Duran (45) are the other top five collectors.
The following species were rejected from the list for the stated reasons:
- Ephedra viridis. The voucher was of a male plant, which cannot be reliably determined. The expected species here is E. aspera. Jon Rebman checked the voucher on 2 January 2014 and changed the determination to E. aspera.
- Ephedra nevadensis. When Tom asked Jon about these vouchers, Jon looked at them and found that all of them were also male plants. There is no evidence at the moment that E. nevadensis exists in San Diego County.
- Ephedra trifurca. This is almost surely a misdetermined voucher, since this species lives in dry sand dune areas, with the closest known locations in Imperial County. One duplicate of this voucher is determined as E. californica, a much-more-likely determination.
- a field survey on 3 March 2014 of 2.0 miles of Hornblende Canyon, by Tom Chester, Kate Harper, Adrienne Ballwey, Ted Caragozian, RT Hawke, and Shaun Hawke. Kate also botanized Hornblende Canyon on 25 February 2014 on a fast-paced hike and found a few species then that we didn't record on 3 March 2014. The route covered is shown in blue in Fig. 1.
- a field survey on 7 March 2014 of 1.6 miles of Cool Canyon, by Tom Chester, Kate Harper, RT Hawke, and Shaun Hawke.
The field surveys were done in a very dry year, so many annual species were missing, and the number of plants observed for annual species that were present are undoubtedly very much lower than would be observed in a wetter year.
The union of the above lists contains 262 taxa. To make the Checklist more complete for use in future fieldwork, the Checklist includes an additional 26 species found in a survey of nearby Rainbow Canyon and Box Canyon. Some of those species may not actually be present in southeast Granite Mountain.
Fig. 2 shows the voucher locations and some of the localities.
Fig. 2. Geographic locations of vouchers (red dots) in a rectangle containing the se Granite Mountain area. Vouchers are almost entirely solely from the base of Granite Mountain, except for Cool Canyon.
Checklist for southeast Granite Mountain
The version of the Cool Canyon Flora used here is out of date; see Flora of Cool Canyon for a later version.
The columns with the header #Pls give the minimum number of plants observed in Cool Canyon (CL) and Hornblende Canyon (HB). Additional species for both canyons are noted from vouchers, marked with V. Additional species in Hornblende Canyon are noted from online photos by Carla Hoegen and Fred Melgert, P for photos from the lower canyon (4 species), and U for photos on a trip through the length of the canyon to Granite Peak (2 species).
Our survey of Hornblende Canyon covered the first 2.0 miles, elevations 2400 to 3100 feet.
Our survey of Cool Canyon covered 1.6 miles, consisting of 0.93 miles of the main canyon up to the junction with the uppermost tributary on the right; 0.15 miles of the tributary from the west; and 0.55 miles of the uppermost tributary on the right, elevations 2600 to 3400 feet.
The column labeled #V gives the number of vouchers for each taxon from the Consortium, with a maximum value of 9. Vouchers are primarily from 2300 to 2800 feet elevation, with a small number from 3000 to 4000 feet, and one voucher from 4400 feet elevation.
The vouchers in Cool Canyon are primarily from 2400 to 2800 feet elevation (108 out of 125 with elevations), with the rest from 3000 to 4000 feet.
If there is no entry in any of the last three columns, the species was from the Rainbow Canyon / Box Canyon surveys (example: Justicia californica).
Version for printing, without lines and other text on this page: html (8 pages) or pdf Clickbook booklet (2 double-sided pages). (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/)