Bloom Reports from the Anza-Borrego Desert: 2011-2012

wishbone plant, Mirabilis bigelovii var. retrorsa
Photograph of flower of Mirabilis bigelovii var. retrorsa
spearleaf, Matelea parvifolia
Photograph of Matelea parvifolia

Pictures taken on 6 January 2012 on the PCT above Scissors Crossing, in San Felipe Valley north of SR78. The Mirabilis bigelovii flower is the size of your thumbnail. The Matelea parvifolia flower is the size of one fourth of your thumbnail. Those are fingers holding the Matelea flower for the photo.

Table of Contents

Rainfall This Season

Annual Germination, Growth and Blooms
     General Requirements for Annual Germination
     Bad Bloom Years Are All The Same; Good Bloom Years Are All Different
     Peak Bloom: What Does That Mean?
     Summary of Annual Germination, Growth and Blooms in 2010-2011

     Detailed Germination, Growth and Bloom Reports From Each Hike
     Pictures From Each Hike

How Long Will An Annual Bloom Last
     General Factors
     Predictions for This Year

Species in Bloom On Each Trip
     Number of Species and Plants in Bloom On Each Trip
     List of Species in Bloom On Each Trip, With Photographs
     Pictorial Gallery of Species in Bloom, organized by flower color

Links to Other Webpages on Anza-Borrego Desert State Park Blooms


This bloom report page reports the bloom status in Anza-Borrego Desert State Park and nearby areas below 3000 feet elevation. Most observations are typically at about 1000 feet elevation. The 2009-2010 page covered the same area, whereas the 2008-2009 and 2009-2010 pages were restricted to the Borrego Desert portion of the Park.

This page gives information about the 2011-2012 bloom for all species in this area, with emphasis on the annuals that are responsible for the widespread showy blooms that appear in some years on the desert floor. The date of the last update to the text of this page is given at the bottom of this page. However, the plots below showing the progress of the bloom are always kept up to date, even if this page hasn't been recently updated otherwise.

The plots below also show the progress of the bloom in 2008-2009, 2009-2010, and 2010-2011. For detailed progress of the bloom in those years, see 2010-2011 Blooms and the links therein.

In addition to specific information about current conditions, this page also gives some general information on what is needed to germinate those annuals, and what is needed to sustain the annual bloom.

The information here is by no means a definitive list to what is blooming at all locations in the Anza-Borrego Desert; it only records the species we've seen in bloom on trips that occur roughly every fourth day, occasionally augmented by observations from other people. Because the locations change, the numbers of species in bloom, and the number of plants in bloom, cannot usually be directly compared from trip to trip. However, the information here will give the reader an idea of what the bloom is doing in the Anza-Borrego Desert.

Note that there is often quite a difference in the annual bloom between the moister canyons west of Borrego Springs and the drier areas around the Badlands. Similarly, even within those canyons on the west, there can be large differences between the north-facing and south-facing slopes, and between canyons with permanent water, like Borrego Palm Canyon, and drier canyons. In the drier areas to the east, there can be large differences between the edges of washes and the middle of washes, and between shady canyons and open areas. Location matters!.

The locations for each hike are in the detailed reports below; sometimes more information is given in Botanical Trail Reports in Chronological Order, which usually include more information about the bloom on each trip.

Rainfall This Season

Rainfall is the most important determinant of blooms. Summer monsoonal rainfall germinates summer annuals and stimulates some perennial plants to bloom in the late summer and fall. Fall / winter Pacific storm rainfall germinates the late winter / spring annuals, and causes the usual late winter / spring bloom in the desert. See the next section for more information.

Summer monsoonal rainfall is from thunderstorms, is extremely spotty in coverage, and does not occur every year in sufficient amounts to stimulate blooms.

Fall / winter rainfall is usually highest on the mountain slopes, especially on the west edge of the Borrego Desert, and falls off dramatically with lower elevation to the east. This occurs whenever our rainfall is mostly orographic, and the storm winds are from the west. However, when rainfall is from convection, or if the storm winds are from the east, the deserts can at times get more rainfall than the coast. (See Precipitation types.)

In addition to desert stations, we've also given the rainfall from Tom's house in Fallbrook, on the coastal side at 680 feet elevation, to show the large difference in rainfall between the wet side of the mountains and the dry side.

Table 1 gives the storm totals, in inches, as of the last day of each storm. The storm totals were taken from the Weather Service Rainfall Storm Summary, except for Fallbrook, which is the amount recorded at my house. Occasionally other stations are missing in that report; if so, totals are taken from the Rainfall Summary Map. Rainfall reports for Ocotillo Wells are reported here for the month to date.

If a station didn't appear in the summary, or we couldn't find it elsewhere on line, we usually assumed the rainfall total was zero. Although this assumption is probably usually correct, it is not necessarily always valid since missing data plague all rain reports. In a few cases, when it was clear that some rainfall must have been received at those missing stations, we've guesstimated the rainfall.

Note that the total rainfall at the bottom of the table is since 13 September, since rain that falls earlier doesn't germinate the desert annuals (see below). This rainfall total may be different from the rainfall reported by the Anza-Borrego Desert State Park Visitor Center using the normal California rainfall year that begins on 1 July. Also, the total rainfall sometimes contains rainfall in Fallbrook not reported in the table if there was no major rainfall in the desert.

Table 1. Major Rainfall Events Since 13 September 2011

End DateFallbrookRanchitaSan FelipeAgua CalienteBorrego SpringsOcotillo Wells
9/13/20110.00   0.240.28
10/5/20110.83   0.000.00
Total All Rain
to 1/24/12

As of 11/16/11, the rainfall total for the 2011-2012 year reported at the Visitor Center, measured at the nearby Colorado District Headquarters, was 1.31 inches (data from Mary Jo Churchwell), compared to the Borrego Springs NWS total of 0.66 inches. The extra amount at the Visitor Center either included some monsoonal rainfall before 9/13/11, or represented heavier rainfall at that location on 9/13/11 and/or 11/12/11.

Annual Germination, Growth and Blooms

General Requirements for Annual Germination

There are two main rain windows for annual germination in the Borrego Desert: monsoonal / summer rainfall, received from thunderstorms in July, August and September, and fall / winter rainfall received from October through January.

Monsoonal rainfall germinates a handful of summer annuals that bloom in September and October. Occasionally, fall / winter rainfall occurring in October will germinate some of these summer annuals.

Our most common summer annuals are listed in Table 2.

Table 2. Summer Annuals Germinated by Monsoonal Rainfall

Scientific nameCommon NameFamily
Amaranthus fimbriatusfringed amaranthAmaranthaceae
Aristida adscensionissix-weeks three-awnPoaceae
Boerhavia coulteriCoulter's spiderlingNyctaginaceae
Boerhavia intermediafivewing spiderlingNyctaginaceae
Boerhavia wrightiiWright's spiderlingNyctaginaceae
Bouteloua aristidoides var. aristidoidesneedle gramaPoaceae
Bouteloua barbata var. barbatasix-weeks gramaPoaceae
Chamaesyce micromeraSonoran spurgeEuphorbiaceae
Chamaesyce setilobaYuma spurgeEuphorbiaceae
Datura discolordesert thornappleSolanaceae
Ditaxis neomexicanaNew Mexico ditaxisEuphorbiaceae
Kallstroemia californicaCalifornia caltropZygophyllaceae
Mollugo cervianacarpet-weedMolluginaceae
Stillingia spinulosaannual stillingiaEuphorbiaceae

Most of these summer annuals won't be seen in a given year at any time unless there has been sufficient summer rainfall (Aristida adscensionis is one of the few summer annuals that is also a spring annual). Good monsoonal rainfall occurs in fewer than half of all years. Monsoonal rainfall is always spotty, with thunderstorms soaking an area of perhaps one square mile, and not touching surrounding areas.

The rest of this section discusses only the "normal" annuals seen by most visitors to the Borrego Desert in the late winter and early spring.

The timing of fall / winter rainfall is extremely important for the annual bloom. Rainfall received in the summer and early fall will not germinate the annuals that bloom in February and March. Rainfall received after January will either not germinate those annuals, or will germinate them too late for them to produce a robust bloom in most years. Thus rain must fall in October, November, December and/or January in order to germinate the annuals that produce the showy mass displays. The potential showiness of the bloom declines when the germinating rainfall gets later in January, since the annuals don't have enough time to grow very large before the increasing heat of March ends their bloom.

The amount in a single storm is also important. Native annuals require at least about an inch of rainfall, received over no longer than a period of something like several days, in order to germinate. Our native annuals have learned the hard way that less rainfall doesn't guarantee enough moisture in the soil for them to produce seeds. Many annuals won't even germinate with two inches of rainfall in the Badlands and similar soils.

Unfortunately, non-native annuals can germinate on less rainfall, and can sometimes get a head start over our native annuals if we get a first rainfall much less than an inch.

See Predicting Desert Wildflower Blooms - The science behind the spectacle from the Arizona-Sonora Desert Museum for information relating to Arizona desert blooms. Note, however, that there is a big difference between the Sonoran Desert germination in Tucson and in Borrego Springs.

Germinating rainfall typically occurs in Tucson in October and November, whereas it typically occurs in Borrego Springs in December and January. See Monthly average rainfall in Tucson and Borrego Springs from September to February (in the plot, month 13 is January and month 14 is February). Tucson receives an average of 1.5 inches of rain in October and November, whereas Borrego Springs receives an average of only 0.6 inches then, not enough to germinate annuals then in most years. Borrego Springs receives an average of 2.0 inches of rain in December and January, which is usually enough to germinate annuals there during that period. (As detailed above, since rainfall declines markedly to the east of Borrego Springs, the probability of germination in those areas in a given year declines as well.)

Bad Bloom Years Are All The Same; Good Bloom Years Are All Different

Janice Emily Bowers, with her vast experience in desert blooms, said it best in her book Flowers and Shrubs of the Mojave Desert, 1998, p. 4:

... maybe one in five [springs] will bring a good wildflower display. All bad springs are more or less alike in that wildflowers are scarce or not to be seen, but all good years are different in that no two have the same abundance of flowers or the same combinations of species. This is because different kinds of annual wildflowers have different requirements for germination and growth.

This is just as true for the Borrego and Sonoran Deserts.

Peak Bloom: What Does That Mean?

The term Peak Bloom means different things to different people:

Most of the time, we use the latter definition of Peak Bloom, but we also try to mention when the carpets of flowers are present.

If you are looking for a particular species in bloom, the time of Peak Bloom doesn't matter to you; you want to know only when that species is in bloom. Plant species bloom at different times; it is not possible to see every species in bloom even over the time period of a month.

For example, if you want to see the beautiful blooms of beavertail cactus, Opuntia basilaris, you'll need to come just after the showy annual carpets are finished. If you want to see the beautiful flowers of desert-willow, Chilopsis linearis ssp. arcuata, then you'll need to come here in summer, when few species are blooming except for it.

See observed dates of peak bloom in 2008-2009 and in 2009-2010 for various locations.

These annual species produce the showy carpets of flowers:

Other annuals can produce carpets of flowers, but are either more limited in their distribution, such as Bigelow's monkeyflower, Mimulus bigelovii, or purple mat, Nama demissum; or don't produce such showy displays, such as Fremont pincushion, Chaenactis fremontii (since fields of white don't show up well against the whitish background of the desert soil).

Summary of Annual Germination, Growth and Blooms in 2011-2012

Monsoonal rainfall was nearly absent this year. We've observed only some very small patches of small numbers of summer annuals, from roadsides in Culp Valley and near the Second Crossing of Coyote Creek.

The rainfall events of 12 November and 12 December 2011 produced limited to moderate germination of annuals in the canyon bottoms west of Borrego Springs, with very little germination in the hillsides above those canyon bottoms, and very little germination anywhere to the east of Borrego Springs. In the southern part of ABDSP, it produced good germination in Fossil Canyon, and presumably elsewhere in the Coyote Mountains, as shown in this picture of a hillside slope of healthy young plants of Chaenactis carphoclinia, pebble pincushion.

The following pictures show just how bad it was on 18 January 2012 at the beginning of the Hellhole Canyon Trail; at the junction of the Hellhole Canyon Trail and the California Riding and Hiking Trail; at about a half mile up the California Riding and Hiking Trail; and in Little Surprise Canyon. In those pix, germination was only seen in Little Surprise Canyon.

In the lower desert, it is shaping up so far as a poor bloom year, with the best blooms only where moisture is greatest, primarily along roadsides and at the very bottom of canyons.

We are still waiting for enough rainfall to produce widespread germination in areas east of Borrego Springs, which normally occurs in late December to early January.

There are desert areas outside of ABDSP that have good blooms now, from heavy rainfall in September and October 2011, such as lowermost Box Canyon immediately east of Mecca, and the southern boundary of Joshua Tree National Park on Cottonwood Springs Road. RT Hawke discovered both of these areas, fairly limited in size, where much water ponded above dikes.

In ABDSP, specifically, we observed low numbers of annuals of five native species in Borrego Palm Canyon on 12/10/11, accompanied by larger numbers of three non-native annuals. We observed larger numbers of annuals of four native species in Glorietta Canyon on 12/28/11, and smaller numbers of another ten native species, but good germination was confined to patchy small areas.

Germination was almost non-existent along the Villager Peak Trail on 12/15/11 and 12/19/11, with just a few annuals observed in Rattlesnake Canyon above that Trail. Similar almost non-existent germination was observed in Palo Verde Canyon on 12/23/11, and along the lower half of the California Riding and Hiking Trail above Hellhole Canyon on 1/18/12.

On 1/22/12, germination was excellent throughout Fossil Canyon in the Coyote Mountains, just north of the town of Ocotillo and I-8 (not Ocotillo Wells).

Detailed Germination, Growth and Bloom Reports From Each Hike

These reports are just summaries of these conditions from each hike.

See also Detailed Germination, Growth and Bloom Reports From Each Hike in 2010-2011 and 2009-2010.

11/7/11: S22, Coyote Creek Road. Our main goal for this trip was to look for Kallstroemia californica, a summer annual. We didn't actually expect to find it, since the monsoonal rain this year was minimal. But we did find a few summer annuals here and there, such as Chamaesyce micromera and Datura discolor. We found one small patch of summer annuals on the hill above Second Crossing.

On our entire trip, the most abundant species in bloom are Eriogonum elongatum, long-stemmed buckwheat along S22 in Culp Valley; Dicoria canescens, desert dicoria, in the "Zero" Crossing of Coyote Creek in the drainage just south of the pavement's end on Di Giorgio Road; Baccharis salicifolia, mule fat, at Second Crossing; and numerous Fouquieria splendens, ocotillo, blooms along S22 and near Desert Gardens. Altogether, we observed a pretty-remarkable 46 species in bloom, with over 689 plants total in bloom. (No species counts more than 99 plants to that total.) The number of species in bloom was high due to making many stops along Coyote Creek in different habitats.

11/11/11: S22, Tubb Canyon. Tubb Canyon was very dry; even Tubb Spring looked quite dry. Most of the species we recorded as being in bloom on this trip were found along S22. We found a "more typical for this time of year" total of over 226 plants of 24 species in bloom.

11/15/11 S2, Grapevine Canyon, Bitter Creek Canyon, Borrego Springs. The blooming stars of the show in Bitter Creek Canyon were Gutierrezia californica, Ericameria brachylepis, Isocoma acradenia var. eremophila, and Eriogonum wrightii var. nodosum, California matchweed, boundary goldenbush, solitary-leaved alkali goldenbush, and Wright's buckwheat, with over 100 plants of each species in bloom except for about 50 plants of Wright's buckwheat. Although the soil was moist, we found only a few germinated annuals, two non-natives: Erodium cicutarium, redstem filaree, and Bromus madritensis ssp. rubens, red brome, and one native: Pholistoma membranaceum, white fiesta flower.

Overall on our trip, including the driving portion along S2 in San Felipe Valley below 3000 feet elevation, we found over 553 plants of 25 species in bloom.

11/22/11: S2, SR78, Pinyon Wash, Pinyon Canyon, Harper Flat. Although the soil in this area was moist, we found very little germination so far, just a few scattered Brassica tournefortii, Sahara mustard, along with one of its typical ~one inch diameter clumps containing 50 crowded plants.

Our drive along Pinyon Wash was filled with Chrysothamnus paniculatus, punctate rabbitbrush, in glorious full bloom. We had no idea there were so many plants of this species here! We'd been seeing a handful of plants along SR78, but Pinyon Wash contains the mother lode for this plant in this area. There were a number of chuparosa and ocotillo in bloom in the wash as well, with many ocotillo fully leafed out. Pinyon Canyon had a number of Eriogonum wrightii var. nodosum, Wright's buckwheat, in full bloom.

Overall on our trip, including the driving portion along S2 in San Felipe Valley below 3000 feet elevation, we found over 341 plants of 15 species in bloom.

11/30/11: Wilson Trail. This trip was at 4,000 feet elevation, well above the cutoff of 3,000 feet elevation for this page, so is not included in the plots and tables below. The only germination was abundant and widespread non-native Erodium cicutarium, redstem filaree, which is able to germinate at cool temperatures and thus gets a head start on the native annuals. This is probably a major reason behind its dominance in many places in Culp Valley.

12/4/11: S2, SR78, Fish Creek, Wind Caves Trail. Although this area had received rainfall, we saw no annual germination. Outside of Fish Creek itself, the plants looked pretty pathetic overall, typical of the end of the drought season. But some plants in the wash, with the higher groundwater table, looked pretty good. The Isocoma acradenia was in full bloom, and we even saw one plant each of Astragalus crotalariae, Salton milk-vetch, and Xylorhiza orcuttii, Orcutt's woody-aster, in bloom.

On our entire trip, including the drive along S2 and SR78, we saw over 241 plants of 21 species in bloom.

See Wayne Armstrong's Pictures from this trip.

12/10/11: S22, Borrego Palm Canyon. This was a delightful trip, since there were a number of baby annuals of five native species, unfortunately accompanied by larger numbers of three non-native annuals. The most abundant annuals were the non-native Brassica tournefortii, Saharan mustard and Bromus madritensis, red brome, and the native Pholistoma membranaceum, white fiesta flower, with hundreds of seedlings of each species. We saw lesser numbers of Phacelia distans, common phacelia, and the non-native Erodium cicutarium, redstem filaree.

On our entire trip, including the drive along S22, we saw over 373 plants of 16 species in bloom.

See Wayne Armstrong's Pictures from this trip.

12/15/11: S22, Fonts Point Wash, Villager Peak Trail, lower Rattlesnake Canyon. No germination was noted along the Villager Peak Trail, and only a handful of individual seedlings were noted in Rattlesnake Canyon, from several native species and from Brassica tournefortii.

On our entire trip, including the drive along S22 and a stop in Fonts Point Wash, we observed over 170 plants of 17 species in bloom.

See Wayne Armstrong's Pictures from this trip.

12/19/11: S22, Villager Peak Trail, upper Rattlesnake Canyon. Germination in upper Rattlesnake Canyon was almost as poor as in lower Rattlesnake Canyon, with only a few spots having more than just a few seedlings.

On our entire trip, including the drive along S22, we observed over 282 plants of 18 species in bloom.

12/23/11: S22, Palo Verde Canyon. Germination was essentially non-existent in Palo Verde Canyon.

On our entire trip, including the drive along S22, we observed over 222 plants of just 10 species in bloom.

12/28/11: S22, Glorietta Canyon. We observed good numbers of annuals of four native species in Glorietta Canyon on 12/28/11, and smaller numbers of another ten native species. However, good germination was confined to patchy fairly small areas, mostly in the washes and canyon floors, with little germination on hillsides.

On our entire trip, including the drive along S22, we observed over 236 plants of just 8 species in bloom.

1/6/12: S2, PCT North of SR78 at Scissors Crossing. Some native germination was observed, but 99% of all the seedlings were from two non-native species, Erodium cicutarium, redstem filaree; and Bromus madritensis rubens, red brome. Redstem filaree was everywhere, whereas red brome was mostly on north-facing slopes.

On our entire trip, including the drive along S2, we observed over 142 plants of 24 species in bloom.

1/8/12: ABF Rebman Field Trip: S3, SR78, S2, Pinyon Mountain Road. No intensive field survey was conducted. The list of plants in bloom were just the ones noted during the trip. Just 18 plants of 8 species were seen in bloom.

1/10/12: S2, PCT North of SR78 at Scissors Crossing. Same conditions as on 1/6/12 in the area surveyed both days, plus we observed significant native annual germination in the sandy area north of the large parking area on S2 a bit north of Scissors Crossing, including Camissonia pallida, Loeseliastrum schottii and Camissonia californica.

On our entire trip, including the drive along S2, we observed over 209 plants of 26 species in bloom.

1/18/12: S22, California Riding and Hiking Trail from Hellhole Canyon toward Culp Valley, Little Surprise Canyon. Nearly all the species we observed in bloom were from two stops along S22 on Montezuma Grade. Germination was shockingly absent along nearly the entire length of the California Riding and Hiking Trail, with just a handful of Cryptantha and Chaenactis carphoclinia seedlings in just a few areas, accompanied by just three small areas where Pholistoma membranaceum, white fiesta flower, has germinated, and one sandy area along a drainage that had a hundred plants of Pectocarya recurvata, curvenut combseed, each about one inch high with a single very tiny flower. There was very sparse germination in Little Surprise Canyon, with some of the tiny Senecio mohavensis plants producing just a few tiny buds.

If you blinked while hiking or driving past any of those areas, none of those plants would have been seen.

The following pictures show just how bad it was at the beginning of the Hellhole Canyon Trail; at the junction of the Hellhole Canyon Trail and the California Riding and Hiking Trail; at about a half mile up the California Riding and Hiking Trail; and in Little Surprise Canyon. In those pix, germination was only seen in Little Surprise Canyon.

On our entire trip, including the drive along S2, we observed over 298 plants of 38 species in bloom.

1/22/12: S2, Fossil Canyon. We made three stops along S2 to check on the germination:

The total number of blooms on our entire trip was low, only 140 plants of just 24 species in bloom.

Pictures From Each Hike

See Photo Gallery of Desert Species Observed in Bloom for photographs organized by flower color. The date and location of each picture are given in that table.

Most of the rest of Tom's pictures were taken for scientific purposes, and not specifically to show anything about the bloom. However, they may be of interest to people showing some aspects of what the bloom was like on a given date. Tom's pictures are not even on standard webpages; Table 3 gives links to a directory and you have to click on the link for each picture to see it. Scientific names are used almost exclusively for the picture names.

The context for most of these pictures is sometimes given in the botanical reports from each hike.

Table 3. Links to Directories With Pictures From Each Trip

November 07
November 11
November 15
November 22
November 30
December 4
December 15

See also Pictures From Each Hike in 2010-2011 and 2009-2010 (caution: some pictures may have been deleted due to web space limitations).

How Long Will An Annual Bloom Last

General Factors

Past Rainfall, Future Rainfall, and Heat are the main factors determining how long an annual bloom will last on the desert floor at about 1000 feet elevation:

Predictions for This Year

As of 19 January 2012, unless we get further rainfall this month, areas east of Borrego Springs will have essentially no annual show at all. Canyons west of Borrego Springs will have a very poor annual show, since the limited number of annuals will each produce just a few flowers. The show will get better as one goes up in elevation, with areas at 3000 feet and above having a decent year.

With further rainfall, areas in the southernmost part of San Diego and Imperial Counties should have a good display, at least in the canyons.

Species in Bloom On Each Trip

Number of Species and Plants in Bloom On Each Trip

Five plots are given below; each plot has this year's bloom data as well as last year's bloom data for comparison:

The plots and the table here must be interpreted cautiously, for at least three reasons:

Figure 1. Number of Species in Bloom on Each Trip

Graph showing the number of species found in bloom on each trip for 2008-2009 and 2009-2010

Figure 2. Number of Plants in Bloom on Each Trip

Graph showing the number of individual plants found in bloom on each trip for 2008-2009 and 2009-2010

Figure 3. Cumulative Number of Species Seen in Bloom From All Trips

Graph showing the cumulative number of species found in bloom for trips in 2008-2009 and 2009-2010

Figure 4. Cumulative Number of Annual Species Seen in Bloom From All Trips

Graph showing the cumulative number of annual species found in bloom for trips in 2008-2009 and 2009-2010

Figure 5. Percent of All Species Seen in Bloom From All Trips That Are Annuals

Graph showing the percent of all species cumulatively seen in bloom that are annuals for 2008-2009 and 2009-2010

Table 4 gives the numbers used for the above plots, for the last two months. The individual observations used to obtain these numbers are in the List of Species in Bloom On Each Trip.

Table 4. Number of Species and Total Number of Plants in Bloom on Each Trip

Number of11/0711/1111/1511/2212/412/1012/1512/1912/2312/281/61/81/101/181/22

List of Species in Bloom On Each Trip, With Photographs

Table 5 gives the number of plants observed to be in bloom for each species on each hike, with a maximum value of 99 plants for each species. This maximum value prevents one species from dominating the total plants in bloom, and makes it much easier to keep track of the bloom.

Because the hike locations vary, some species will not be present on every hike, so the lack of an entry for a given hike says nothing about whether that species is blooming elsewhere.

The Checklist is sorted first by category, with dicots before monocots, and then by family and scientific name. The Family and Scientific Name are from the Jepson Manual. An asterisk before the Common Name indicates a non-native taxon.

See Plant Family Abbreviations to obtain the full family name from the abbreviations used in the table below.

The Checklist has thumbnail photographs for most of the species, all of which were taken in the Borrego Desert. Clicking on the thumbnail photograph gives a larger version equal in size to the ones at the top of this page.

All the larger versions are also presented in Pictorial Gallery of Species in Bloom, organized by flower color, and with the location and date of each picture.

All pictures were taken by Tom, with a Sony Point and Shoot T9 camera except the following:

This table gives the number of plants in bloom only in the last two months, in order to remove species that are probably no longer blooming.

Some species that have bloomed in the Borrego Desert are not listed here, since we never observed them in bloom. Such species are found only in a few locations, and we either never visited those locations or they bloomed in between our visits to their location.

Of course, species that bloom later in the year, and species that do not have flowers (ferns, etc.) are not present in this list, so it is not the equivalent of a plant checklist for the Borrego Desert.

An asterisk before the common name indicates a non-native species.

Table 5. List of Species in Bloom On Each Trip, with Number of Plants Observed in Bloom

#FAMScientific NamePix(*)Common Name Number of Plants in Bloom
1ACAJusticia californicaPhotograph of flower of Justicia californicachuparosa220205059952 20   152
2AMAAmaranthus fimbriatusPhotograph of flower of Amaranthus fimbriatusfringed amaranth3              
3ASCAsclepias albicansPhotograph of flower of Asclepias albicanswhite-stemmed milkweed    1          
4ASCAsclepias subulataPhotograph of flower of Asclepias subulatarush milkweed1     32       
5ASCMatelea parvifoliaPhotograph of flower of Matelea parvifoliaspearleaf          1 1  
6ASTAdenophyllum porophylloidesPhotograph of flower of Adenophyllum porophylloidesSan Felipe dogweed31     4  2 110 
7ASTAmbrosia acanthicarpaPhotograph of flower of Ambrosia acanthicarpabur-ragweed2              
8ASTAmbrosia dumosaPhotograph of flower of Ambrosia dumosaburroweed1              
9ASTBaccharis salicifoliaPhotograph of flower of Baccharis salicifoliamule fat25              
10ASTBebbia juncea var. asperaPhotograph of flower of Bebbia juncea var. asperasweetbush1155223   24 2510
11ASTBrickellia desertorumPhotograph of flower of Brickellia desertorumdesert brickellia 3             
12ASTBrickellia frutescensPhotograph of flower of Brickellia frutescensshrubby brickellia   1           
13ASTChrysothamnus paniculatusPhotograph of flower of Chrysothamnus paniculatuspunctate rabbitbrush1 59925     6    
14ASTConyza canadensisPhotograph of flower of Conyza canadensishorseweed99              
15ASTDicoria canescensPhotograph of flower of Dicoria canescensdesert dicoria99     1        
16ASTEncelia actoniPhotograph of flower of Encelia actoniActon encelia    1   2      
17ASTEncelia farinosaPhotograph of flower of Encelia farinosabrittlebush     3111   1202
18ASTEncelia frutescensPhotograph of flower of Encelia frutescensbutton encelia      1        
19ASTEricameria brachylepisPhotograph of flower of Ericameria brachylepisboundary goldenbush10 99    5  3 18 
20ASTGnaphalium luteo-albumPhotograph of flower of Gnaphalium luteo-album*common cudweed5              
21ASTGutierrezia californicaPhotograph of flower of Gutierrezia californicaCalifornia matchweed2 9930      11 153 
22ASTGutierrezia sarothraePhotograph of flower of Gutierrezia sarothraematchweed 2             
23ASTHeterotheca grandifloraPhotograph of flower of Heterotheca grandifloratelegraph weed  50302      2   
24ASTIsocoma acradenia var. acradeniaPhotograph of flower of Isocoma acradenia var. acradeniaalkali goldenbush  1 1          
25ASTIsocoma acradenia var. eremophilaPhotograph of flower of Isocoma acradenia var. eremophilasolitary-leaved alkali goldenbush  99 40          
26ASTPalafoxia arida var. aridaPhotograph of flower of Palafoxia arida var. aridadesert needle20   2          
27ASTPectis papposa var. papposaPhotograph of flower of Pectis papposa var. papposachinch-weed3              
28ASTSenecio flaccidus var. monoensisPhotograph of flower of Senecio flaccidus var. monoensisMono ragwort1              
29ASTStephanomeria exigua ssp. exiguaPhotograph of flower of Stephanomeria exigua ssp. exiguaslender wreathplant  1       2 2  
30ASTStephanomeria pauciflora var. paucifloraPhotograph of flower of Stephanomeria pauciflora var. pauciflorawire-lettuce3320515155252  1 
31ASTViguiera parishiiPhotograph of flower of Viguiera parishiiParish's viguiera10 1123 5    4202
32ASTXylorhiza orcuttiiPhotograph of flower of Xylorhiza orcuttiiOrcutt's woody-aster    1          
33BIGChilopsis linearis ssp. arcuataPhotograph of flower of Chilopsis linearis ssp. arcuatadesert-willow15              
34BORCryptantha angustifoliaPhotograph of flower of Cryptantha angustifolianarrow-leaved cryptantha             1 
35BORCryptantha maritimaPhotograph of flower of Cryptantha maritimaGuadalupe cryptantha             1 
36BORCryptantha racemosaPhotograph of flower of Cryptantha racemosabushy cryptantha    1        6 
37BORPectocarya recurvataPhotograph of flower of Pectocarya recurvatacurvenut combseed             995
38BORPlagiobothrys arizonicusPhotograph of flower of Plagiobothrys arizonicusArizona popcorn flower              10
39BORTiquilia palmeriPhotograph of flower of Tiquilia palmeriPalmer's coldenia10              
40BRABrassica tournefortiiPhotograph of flower of Brassica tournefortii*Asian mustard             55
41BRAHirschfeldia incanaPhotograph of flower of Hirschfeldia incana*shortpod mustard   2           
42BRALyrocarpa coulteri var. palmeriPhotograph of flower of Lyrocarpa coulteri var. palmeriCoulter's lyrepod         1     
43CACMammillaria dioicaPhotograph of flower of Mammillaria dioicaCalifornia fish-hook cactus             1 
44CAPIsomeris arboreaPhotograph of flower of Isomeris arboreabladderpod5 1            
45CHEAtriplex hymenelytraPhotograph of flower of Atriplex hymenelytradesert holly              1
46CUSCuscuta californica var. papillosaPhotograph of flower of Cuscuta californica var. papillosapapillate dodder15              
47EUPChamaesyce albomarginataPhotograph of flower of Chamaesyce albomarginatarattlesnake weed  1            
48EUPChamaesyce melanadeniaPhotograph of flower of Chamaesyce melanadeniared-gland spurge5 10    10  311510 
49EUPChamaesyce micromeraPhotograph of flower of Chamaesyce micromeraSonoran spurge10              
50EUPChamaesyce pediculiferaPhotograph of flower of Chamaesyce pediculiferaCarrizo Mountain spurge              20
51EUPChamaesyce polycarpaPhotograph of flower of Chamaesyce polycarpasmall-seeded spurge51020  10  10 10 3  
52EUPChamaesyce setilobaPhotograph of flower of Chamaesyce setilobaYuma spurge     25  2      
53EUPCroton californicusPhotograph of flower of Croton californicusCalifornia croton101    1010       
54EUPDitaxis lanceolataPhotograph of flower of Ditaxis lanceolatanarrowleaf ditaxis 1  199    10 521
55EUPDitaxis neomexicanaPhotograph of flower of Ditaxis neomexicanaNew Mexico ditaxis51513    5  11   
56EUPEuphorbia erianthaPhotograph of flower of Euphorbia erianthabeetle spurge             2 
57EUPStillingia linearifoliaPhotograph of flower of Stillingia linearifolialinear-leaved stillingia3           3  
58FABAstragalus crotalariaePhotograph of flower of Astragalus crotalariaeSalton milk-vetch    1          
59FABCaesalpinia virgataPhotograph of flower of Caesalpinia virgatawand holdback              6
60FABLotus rigidusPhotograph of flower of Lotus rigidusdesert lotus             4 
61FABLotus salsuginosus var. brevivexillusPhotograph of flower of Lotus salsuginosus var. brevivexillusshort-bannered coastal lotus             3 
62FABLotus scoparius var. brevialatusPhotograph of flower of Lotus scoparius var. brevialatusshort-winged deerweed          2 232
63FABPsorothamnus emoryiPhotograph of flower of Psorothamnus emoryiEmory's indigo-bush15     210       
64FOUFouquieria splendens ssp. splendensPhotograph of flower of Fouquieria splendens ssp. splendensocotillo502054099534  1  67
65GERErodium cicutariumPhotograph of flower of Erodium cicutarium*redstem filaree          20 351030
66LAMHyptis emoryiPhotograph of flower of Hyptis emoryidesert-lavender231 150221  1 1014
67LOAPetalonyx thurberi ssp. thurberiPhotograph of flower of Petalonyx thurberi ssp. thurberiThurber's sandpaper-plant99              
68LYTLythrum californicumPhotograph of flower of Lythrum californicumCalifornia loosestrife3              
69MALHibiscus denudatusPhotograph of flower of Hibiscus denudatusrock hibiscus           1   
70NYCAbronia villosa var. villosaPhotograph of flower of Abronia villosa var. villosahairy sand-verbena2              
71NYCAllionia incarnataPhotograph of flower of Allionia incarnatatrailing four o'clock2   1          
72NYCMirabilis bigelovii var. retrorsaPhotograph of flower of Mirabilis bigelovii var. retrorsawishbone plant 2        2 23 
73ONACamissonia cardiophylla ssp. cardiophyllaPhotograph of flower of Camissonia cardiophylla ssp. cardiophyllaheartleaf sun-cup21   1       6 
74ONACamissonia pallida ssp. pallidaPhotograph of flower of Camissonia pallida ssp. pallidapale sun-cup              3
75ONAEpilobium canum ssp. latifoliumPhotograph of flower of Epilobium canum ssp. latifoliummountain California-fuchsia  5            
76POLEriogonum davidsoniiPhotograph of flower of Eriogonum davidsoniiDavidson's buckwheat22     999999  51 
77POLEriogonum deflexum var. deflexumPhotograph of flower of Eriogonum deflexum var. deflexumflat-topped buckwheatRT   5          
78POLEriogonum elongatum var. elongatumPhotograph of flower of Eriogonum elongatum var. elongatumlong-stemmed buckwheat9999 20 9999999999   1 
79POLEriogonum fasciculatum var. polifoliumPhotograph of flower of Eriogonum fasciculatum var. polifoliumCalifornia buckwheat221010  1   1 211
80POLEriogonum gracile var. incultumPhotograph of flower of Eriogonum gracile var. incultumslender buckwheat  15       1    
81POLEriogonum inflatumPhotograph of flower of Eriogonum inflatumdesert trumpet3010110301510105610 351
82POLEriogonum plumatellaPhotograph of flower of Eriogonum plumatellayucca buckwheat  20            
83POLEriogonum wrightii var. nodosumPhotograph of flower of Eriogonum wrightii var. nodosumWright's buckwheat 105040 12081410 253 
84ROSPrunus fremontiiPhotograph of flower of Prunus fremontiidesert apricot          112202 
85RUTThamnosma montanaPhotograph of flower of Thamnosma montanaturpentine broom           12  
86SIMSimmondsia chinensisPhotograph of flower of Simmondsia chinensisjojoba              1
87SOLDatura discolorPhotograph of flower of Datura discolordesert thornapple1              
88SOLDatura wrightiiPhotograph of flower of Datura wrightiisacred datura1 11           
89SOLLycium fremontiiPhotograph of flower of Lycium fremontiiFremont box-thorn              3
90SOLNicotiana obtusifoliaPhotograph of flower of Nicotiana obtusifoliadesert tobacco 1          15  
91SOLPhysalis crassifoliaPhotograph of flower of Physalis crassifoliathick-leaved ground cherry 1    1   5 1016
92TAMTamarix ramosissimaPhotograph of flower of Tamarix ramosissima*saltcedar 1             
93VISPhoradendron californicumPhotograph of flower of Phoradendron californicumdesert mistletoe             1 
94ZYGLarrea tridentataPhotograph of flower of Larrea tridentatacreosote bush21           101
95LILAgave desertiPhotograph of flower of Agave desertidesert agave    5 1   49962
96POAAristida adscensionisPhotograph of flower of Aristida adscensionissix-weeks three-awn22  11    20 2510 
97POAAristida purpureaPhotograph of flower of Aristida purpureapurple three-awn      51     1 
98POABouteloua aristidoides var. aristidoidesPhotograph of flower of Bouteloua aristidoides var. aristidoidesneedle grama     7         
99POACynodon dactylonPhotograph of flower of Cynodon dactylon*Bermuda grass1              
100POALeptochloa uninerviaPhotograph of flower of Leptochloa uninerviaMexican sprangletop2              
101POAPennisetum setaceumPhotograph of flower of Pennisetum setaceum*fountain grass             2 
102POAPleuraphis rigidaPhotograph of flower of Pleuraphis rigidabig galleta            1  
103POASchismus barbatusPhotograph of flower of Schismus barbatus*Mediterranean schismus              5

Links to Other Webpages, etc. on Anza-Borrego Desert State Park Blooms

Anza-Borrego Desert Wildflowers: Where and When to Look and latest report (usually from Bill Sullivan) from the Anza-Borrego Desert Natural History Association.

Anza-Borrego Desert State Park official site, with wildflower information on it. Click on the link near the bottom for the Flower Update and Map, which might be updated weekly.

DesertUSA Anza-Borrego Desert State Park Wildflower Reports For 2011

Carol Leigh's California Wildflower Hotsheet has been discontinued as of 30 March 2010, due to people harming some of the wildflower locations reported there, by trampling the wildflowers, picking them, and even lying on them. There's no better advice than what she left her readers with: Please walk gently on this earth.

Anza-Borrego Foundation and Institute Wildflowers and their Anza-Borrego Desert State Park Wildflower Hotline: (760)767-4684. "Information on this recording is updated regularly."

Theodore Payne Wildflower Hotline (Reports begin the first Friday in March 2011)

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Copyright © 2008-2012 by Tom Chester, Kate Harper, and Mike Crouse.
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Updated 24 January 2012