Plant Notes From Car Trip Between Fallbrook and Anza-Borrego State Park

The purpose of this trip was to search for leafy common rabbitbrush, Chrysothamnus nauseosus ssp. consimilis. I've found a number of specimens of Chrysothamnus nauseosus ssp. bernardinus which key out perfectly to consimilis, even though it is quite unlikely that this is their id. Hence I wanted to locate some definite consimilis for comparison.

I hoped to locate some consimilis at The Narrows, a location mentioned in Beauchamp's Flora of San Diego County, and expected to see some in the mountains bordering the desert. I was quite surprised not to find any rabbitbrush at all anyplace. It looked like rabbitbrush has been replaced by Encelia along most of the route, with a few locations having Isocoma.

This page documents the route I took, since it is often just as interesting to note where a species was not observed as where it is observed. I give the identity of all the potential rabbitbrush plants along the way, along with a few other plant notes.

On the first portion of the trip, I noticed that white everlasting, Gnaphalium canescens microcephalum in bloom was obvious even at 45 mph. So I decided to also sample it occasionally to see if I could find fragrant everlasting, Gnaphalium canescens beneolens. I was successful at doing that.

The trip was on Sunday, September 21, 2003, from ~11 a.m. to ~4 p.m. It is of course possible that rabbitbrush may have been present, but not blooming. However, I did recognize the only occurrence of Ericameria pinifolia by observing and recognizing plants that were not blooming, from my car at 40 mph. This bush has a very similar shape to the rabbitbrush that I have seen. Hence if rabbitbrush had been present in any quantity, I most likely would have found it.

All coordinates are from a GPS receiver, and hence the altitude could be off by 100 feet or so. The mileage is measured from the intersection of SR76 and I-15. I drove an extra 0.8 mile to get to stop 2, since I had to backtrack after seeing the Isocoma bush. I also drove into the San Luis Rey Picnic Area, which added a bit of mileage. The Mile Marker along the road is abbreviated MM in the table.

The locations are plotted using Topo! at Level 1 and Level 2, using the levels defined by the program.

Stop #MileLatitudeLongitudeElevation (feet)Location DescriptionComments
119.233.29760-116.919022258SR76Gnaphalium canescens microcephalum (GCM): lvs not decurrent; faint smell; upper cauline lvs spreading
226.633.27500-116.835282336SR76Ericameria parishii - a very healthy bush! MM 43.0
330.133.25389-116.792222541SR76 - San Luis Rey picnic area.The river was flowing strongly.
442.433.23611-116.651392993S22(Lessingia glandulifera or Pectis papposa), Ambrosia acanthicarpa, California aster, telegraph weed, California buckwheat, Stephanomeria exigua
546.333.21833-116.592783396S22Begin burn area. Gnaphalium canescens beneolens!! Upper cauline lvs appressed, ~fragrant, lvs look decurrent, but don't appear to be when I pull them off in the field. But they did at home. Heads very compact, floriferous.
648.333.21278-116.560003695S22Ericameria pinifolia - only beginning ~0.5 mile back, and no more the rest of the trip.
755.333.21750-116.451113179S22, now in Anza-Borrego State ParkHuge honking what looks like nude buckwheat! Encelia farinosa in full bloom; probably Amaranthus fimbriatus, Tribulus terristris, cholla, California buckwheat. Gold patches visible, probably due to Pectis papposa.
857.933.21278-116.422782364S22Parking area with one spanish needles, Palafoxia arida, in bloom; Encelia farinosa, Bebbia juncea, and probably Boerhavia coulteri.
970.033.21056-116.32722515Borrego Springs Road just past Yaqui Pass Road, at La Casa del ZorroArundo donax.
1075.433.16389-116.25361613Borrego Springs Road, Texas Dip, Sal Felipa WashDesert willow, Chilopsis linearis ssp. arcuata, in full bloom.
1180.133.13083-116.300831024SR78, The Narrows Earth TrailHiked around looking for rabbitbrush, for 0.33 miles on the trail and then in the wash on the north side of SR78. Full bloom: Burro-weed, Ambrosia dumosa; Amaranthus fimbriatus; Bouteloua aristidoides^2 everywhere. Some bloom: chuparosa, Justicia californica. Old flower stalks: big galleta, pleuraphis rigida.
1289.333.11472-116.441671975SR78, middle of Sentenac CanyonIsocoma acradenia bracteosa beginning about a half mile earlier; common reed, Phragmites australis.
1391.633.09833-116.470832227SR78, Scissors CrossingIsocoma acradenia still.
1433.06639-116.552782666SR78, Banner Canyon near BannerBeginning of burn area near Banner about a half mile before.
1599.133.08139-116.571113189SR78, middle of Banner CanyonA single (goldenbush?) about a half mile back, unreachable from the road.

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Copyright © 2003-2004 by Tom Chester.
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Comments and feedback: Tom Chester
Updated 14 November 2005.