Bloom Reports from the Anza-Borrego Desert: 2010-2011
Bigelow's monkeyflower, Mimulus bigelovii glandular nemacladus, Nemacladus glanduliferus Pictures of two annual plants taken on 19 January 2011 in Harper Canyon. The Mimulus plant is about the size of your hand; the Nemacladus flower is only a few mm (0.1 inch) across (note the pen tip for scale) Recent updates to this page:
- 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.
- Summary of Annual Germination, Growth and Blooms in 2010-2011 (Updated 1/21/11)
- Predictions for This Year (Updated 1/21/11)
Table of Contents
Introduction
Rainfall This SeasonAnnual 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 HikeHow Long Will An Annual Bloom Last
General Factors
Predictions for This YearSpecies 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 To Date in 2009-2010, organized by flower colorLinks to Other Webpages on Anza-Borrego Desert State Park Blooms
Introduction
I've expanded the scope of this bloom report page in 2010-2011 to include a larger area of the Anza-Borrego Desert State Park and nearby areas, since I plan on botanizing a larger desert area this season than I have in years past. Pages for 2008-2009 and 2009-2010 were restricted to the Borrego Desert portion of the Park.
In all cases, these pages only give the bloom status below 3000 feet elevation. Most observations are typically at about 1000 feet elevation.
This page gives information about the 2010-2011 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 and 2009-2010. For detailed progress of the bloom in those years, see 2009-2010 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 I've seen in bloom on my trips that occur roughly every fourth day. 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. 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. However, when rainfall is from convection, the deserts can at times get more rainfall than the coast. (See Precipitation types.)
In addition to desert stations, I've also given the rainfall from my 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 and the Borrego Badlands / Ocotillo Wells. 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 at here for the month to date.
If a station didn't appear in the summary, or I couldn't find it elsewhere on line, I 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, I've guesstimated the rainfall.
Note that the total rainfall at the bottom of the table is since 1 October, 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 also contains rainfall in Fallbrook not reported in the table if there was no major rainfall in the desert.
Table 1. Major Rainfall Events in the Desert Since 1 October 2010
End Date Fallbrook San Felipe Agua Caliente Borrego Palm Canyon Borrego Springs Ocotillo Wells 10/21/2010 2.28 1.33 1.34 1.98 1.57 1.08 10/25/10-11/28/10 1.81 0 0 0 0 0 12/22/2010 8.26 1.58 0.92 2.59 2.06 0.89 12/26/10-12/30/10 1.53 0 0 0 0 0 1/3/2011 1.02 0.28 0 0.05 0 0 Total All Rain 16.80 3.23 2.33 4.65 3.52 2.01 On 11/24/10, the Visitor Center billboard reported 2.44 inches of rain, compared to the total above of 1.57 inches from the National Weather Service station in Borrego Springs. This may be due to differences in rainfall between stations, or due to rainfall prior to 10/1/10.
Annual Germination, Growth and Blooms
General Requirements for Annual Germination
The timing of 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, and/or December in order to germinate the annuals that produce the showy mass displays.
The amount in a single storm is also important. Native annuals require 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 any less rainfall doesn't guarantee enough moisture in the soil for them to produce seeds.
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. Many of our annual species respond a bit differently, since we have much less monsoonal rain and more winter rain, but some of our species follow the Arizona rules.
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:
- To the casual visitor to the Borrego Desert, it means the time period when there are carpets of showy flowers on the desert floor that will immediately be obvious in a large-scale photograph. As a result, this is also what the Park Staff means by Peak Bloom as well, and what is reported by them in the postcard notifications to those who sign up for that.
Only a few species produce those showy carpets of flowers, and the timing of their bloom does not necessarily correspond to each other, let alone the ~200 other species that bloom in February and March.
Note that other species can produce fields of flowers, but not in the sense of carpets of flowers. For example, brittlebush, Encelia farinosa, can produce very showy displays on hillsides long after the carpets of annuals are gone.
- To a wildflower enthusiast, or a botanist, it might mean the time period when they can see the maximum number of species in bloom on a given one or two day trip. This in general occurs later than the time when showy carpets of flowers are present.
In fact, I have been in the desert at such a time of peak bloom, with perhaps 50 species in full bloom within a mile of my location, and had visitors ask me where the flowers are. Clearly, they were looking for carpets of flowers, and weren't interested in walking around to find all the species in bloom at that location.
Most of the time, I use the latter definition of Peak Bloom, but I 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:
- hairy sand verbena, Abronia villosa
- brown-eyed primrose, Camissonia claviformis
- spectacle-pod, Dithyrea californica
- hairy desert-sunflower, aka desert gold, Geraea canescens
- Arizona lupine, Lupinus arizonicus
- desert dandelion, Malacothrix glabrata
- dune primrose, Oenothera deltoides
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 2010-2011
The widespread rainfall of 1-2 inches in the desert in mid-October 2010 woke up many perennials and shrubs, and began the annual germination.
Interestingly, the October rain germinated both summer annuals such as fivewing spiderling, Boerhavia intermedia; and chinch-weed, Pectis papposa; and winter annuals such as hairy sand verbena, Abronia villosa, all of which are blooming together now in an unusual juxtaposition.
The widespread rainfall of 1-2.5 inches in late December 2010 encouraged further growth of the annuals, and germinated more species.
As of 19 January 2011, on each single day trip we are consistently finding over 1,000 individuals in bloom of at least 40 species. Every trip reveals new species that have just come into bloom, and shows buds on other species that haven't yet bloomed.
The plots below show a consistent upward trend in both the total number of all species, and the total number of annual species, seen in bloom so far. Those plots show that we are now about halfway toward the numbers seen at the time of peak bloom.
In particular, as of 19 January 2011, we have seen 124 different species in bloom this season, out of a typical total of ~200-250 species seen by the end of the desert season.
The plots show that the bloom state this year is about one month earlier than last year.
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 2009-2010.
12/17/10: Villager Peak Trail. Overall on this trip, we saw over 198 plants of 63 species in flower.
12/23/10: Fossil Canyon and Wash, Coyote Mountains. Overall on this trip, we saw over 444 plants of 40 species in flower.
12/27/10: The Domelands, Coyote Mountains. Overall on this trip, we saw over 380 plants of 39 species in flower.
1/6/11: West Butte Borrego Mountain, Borrego Mountain Wash, The Slot. Overall on this trip, we saw over 695 plants of 53 species in flower.
1/11/11: Hawk Canyon, North side Borrego Mountain. Overall on this trip, we saw over 1,089 plants of 53 species in flower.
1/15/11: Coyote Mountain, South Approach. Brittlebush, Encelia farinosa, has now lit up the PegLeg Monument area at the intersection of Henderson Canyon Road and S22, as well as the slopes of Coyote Mountain above it. Emory's rock-daisy, Perityle emoryi, is beginning its display there on the slopes as well. See Picture of both (you have to look hard below the Encelia to see the little dots of white from the first Perityle flowers).
Overall on this trip, we saw over 1,060 plants of 41 species in flower.
1/19/11: Harper Canyon. Carpets of Bigelow's monkeyflower, Mimulus bigelovii, greeted us in places as we hiked the Harper Canyon Jeep Road. One of the biggest surprises was to see tiny plants in flower of glandular nemacladus, Nemacladus glanduliferus, in bloom on the way back, at dusk, that we had walked right past on the way up in harsher mid-day light. We found 12 species in bloom not seen previously this season.
Overall on this trip, we saw over 1,385 plants of 49 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 my 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. My pictures are not even on standard webpages; Table 2 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 2. Links to Directories With Pictures From Each Trip
2010 2011 November 24
November 27December 3
December 13
December 17
December 23
December 27January 6
January 11
January 15
January 19See also Pictures From Each Hike in 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:
- Past rainfall affects how big the plant is, and how many resources it has to keep blooming, especially the root system of the plant and how much moisture is available in the ground. Given enough resources, annuals can withstand conditions that would otherwise abruptly end the bloom.
- Future rainfall can allow a bloom to keep going even if resources are meager. Even annuals near death can produce significant new growth if they receive rainfall.
- Heat is the main factor that terminates a bloom. I've seen a very robust February bloom abruptly end in just two weeks in March when 90° heat begins and is sustained for a few weeks. On the other hand, the bloom can go into April in years with cooler March temperatures.
Predictions for This Year
This is going to be a good bloom year everywhere in the desert due to the two widespread heavy rain events.
If the trends seen in the plots below continue, we'll begin full bloom in early February, and probably get in at least a month of full bloom, and maybe more, before it gets too hot, frying the annuals. Many have been the March's where the bloom was suddenly ended by a spell of hot weather.
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 first two plots, Figures 1-2, show what was observed on each trip, the total number of species in bloom and the total number of plants in bloom. The total number of plants in bloom for each individual species is capped at a maximum of 99 plants.
- The next two plots, Figures 3-4, give the cumulative total numbers from all trips so far this season, of all species seen in bloom and of all annual species that germinated this year and have begun blooming. Thus this does not count any annual species that survived from last year and is now blooming. These cumulative total numbers include the number of species on a given trip as well as those from all trips previous to that trip.
The last plot, Figure 5, gives the percent of the species that have bloomed so far that are annuals.
The plots and the table here must be interpreted cautiously, for at least three reasons:
- First, long hikes will find more plants in bloom than short hikes. For example, the hikes of 12/29/08, 1/2/09 and 1/9/09 were all in Henderson Canyon, but were 4, 7 and 8 miles long, respectively. The increase in the number of plants was due almost entirely to the length covered.
- Second, some areas have a higher species diversity than others, and so will have more species blooming at a given time. For example, on 2/20/09, I botanized the Borrego Badlands, which had significantly fewer species than the Coyote Creek area I had botanized for the previous two trips. As a result, the total number of species observed in bloom skidded from 61 to 35, even though the bloom overall in the Borrego Desert was still getting better. Note that the cumulative number of species, and annuals, seen to be in bloom from all trips that year continued to increase, since the Badlands had some species not found elsewhere.
- In 2009-2010, I began by botanizing the Coyote Creek Area, which had abundant water along the Creek. As a result, I found significantly more species in bloom than I did in 2008-2009, when I began by botanizing the very dry Clark Lake Area.
On 12/1/09, I visited an area that had received a summer thunderstorm on 5 September 2009, and as a result had many more species in bloom than anyplace else I visited in December 2008 or December 2009.
The curves for November and December for 2008-2009 and 2009-2010 could thus easily have been switched between years if I had also switched areas botanized in each year. (I.e., if I had botanized wet / monsoon storm areas in 2008-2009 and dry areas in 2009-2010.)
In fact, the number of species in bloom on a trip to Clark Valley on 12/19/09 produced almost exactly the same number of species in bloom as the 12/19/08 trip a year earlier.
Figure 1. Number of Species in Bloom on Each Trip
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Figure 2. Number of Plants in Bloom on Each Trip
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Figure 3. Cumulative Number of Species Seen in Bloom From All Trips
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Figure 4. Cumulative Number of Annual Species Seen in Bloom From All Trips
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Figure 5. Percent of All Species Seen in Bloom From All Trips That Are Annuals
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Table 3 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 3. Number of Species and Total Number of Plants in Bloom on Each Trip
Number of 11/11 11/24 11/27 12/3 12/13 12/17 12/23 12/27 1/6 1/11 1/15 1/19 Species 9 23 18 17 15 25 40 39 53 53 41 49 Plants 192 225 322 321 198 198 444 380 695 1089 1060 1385 List of Species in Bloom On Each Trip, With Photographs
Table 4 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 on me 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 To Date in 2009-2010, organized by flower color.
All pictures were taken by myself, with a Sony Point and Shoot T9 camera except the following:
- Mike Crouse contributed the pictures for Camissonia pallida, Crassula connata, Eschscholzia parishii, Fouquieria splendens, Mammillaria dioica, Mirabilis tenuiloba, Penstemon clevelandii var. connatus, Prunus fremontii, and Ribes indecorum, using either a Cannon Point and Shoot SD1100IS or SD1200IS.
- Bill Sullivan contributed the pictures for Oenothera elata ssp. hirsutissima and Mimulus cardinalis.
This table gives the number of plants in bloom only in the last two months.
Some species that have bloomed in the Borrego Desert are not listed here, since I never observed them in bloom. Such species are found only in a few locations, and I either never visited those locations or they bloomed in between my 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.
Table 4. List of Species in Bloom On Each Trip
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 2010
Carol Leigh's California Wildflower Hotsheet
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 on 5 March 2010)
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Copyright © 2008-2011 by Tom Chester.
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Comments and feedback: Tom Chester
Updated 21 January 2011.