Bloom Reports from the Anza-Borrego Desert: 2021-2022

Table of Contents

Latest Summary of Bloom Status
Bloom Reports from Individual Hikes This Season
Links to Other Webpages on Anza-Borrego Desert State Park Blooms
Background Information for Bloom Reports from the Anza-Borrego Desert
Older Bloom Reports from 2009 to present

Fig. 1. Left: Proboscidea althaeifolia, desert unicorn plant. Right: Senna covesii, desert senna. Click on the pix to get views of entire plants.

Both pix by Jim Roberts. The linked pix of the Proboscidea is also by Jim Roberts. The linked pix of the Senna is by Nancy Accola. All pix were taken on 19 August 2021.

Latest Summary of Bloom Status

Summary as of 5 September 2021

Monsoonal thunderstorms, producing enough rain to germinate summer annuals, occurred in scattered locations of parts of the Borrego Desert in late July and early August 2021. These scattered locations are generally places where water ponded during the rains, and are surrounded by areas that have few or no summer annual plants.

Locations with good blooms, and some locations without good blooms, are shown in Fig. 2:


Fig. 2. Locations surveyed on 19 August 2021 (red dots), along with a few areas with conditions observed by Lucinda McDade on 28-29 August 2021. Locations with abundant monsoonal plants are circled in red. The area where nearly every ocotillo had fully leafed out is outlined in solid green, and an approximate area where green ocotillos were reported by McDade is outlined in dashed green. The single location where desert unicorn plants were observed is labeled.

Fred Melgert reported that Ferocactus cylindraceus and Cylindropuntia ganderi have been posted in bloom on Facebook, and McDade observed a single Ferocactus cylindraceus in bloom in the Blair Valley Campground area.

McDade reported that the Borrego Springs immediate area looks like "it has not rained in ages", and that there is a sharp boundary between ocotillos with green leaves in the Yaqui Pass area and leafless ocotillos in the Borrego Valley.

Most of the Pectis papposa plants posted at iNat are from the Blair Valley area, with a small number of widely-scattered locations elsewhere. See all locations of Pectis papposa posted at iNat since 1 August 2021.

McDade reports that the bugs which troubled us on 19 August 2021 were gone by 28 August 2021, making it much more pleasant to enjoy the monsoonal plants.

Bloom Reports from Individual Hikes This Season

The latest bloom reports are given first (i.e., the reports are in inverse order of time).

28-29 August 2021. Lucinda McDade reports:

In Borrego Springs, it looks like it has not rained in ages. As you come out of the canyon (?Yaqui Pass), there is almost a sharp line between ocotillos with leaves and those that look like they have not had leaves in ages.

At Scissors Crossing, can confirm your report that there is little in the way of annuals germinating / up despite clear indication of rain. To what you saw, I can add Krameria in flower and one very happy Physalis crassifolia. Wonder what magical combo of things caused such a massive germination of Boerhavia? They are having a great year!

At the Blair Valley camp area: The Senna are awesome and there were lots of Allionia. Boerhavia in abundance and some probable Mirabilis laevis that were just starting to put out inflorescences. A Ferocactus had decided to flower (across from the camp - on the rocky slope with the Senna). Near the camp itself, adjacent to what had been a large muddy patch where a few yahoos had enjoyed trying to drive their vehicles, there was a very large patch of Hoffmannseggia glauca just coming into flower. That, for me, was the trip highlight - have always loved that plant.

19 August 2021. Tom Chester, Nancy Accola, and Jim Roberts surveyed a route along SR76, SR79, and S2 from the Lake Henshaw area to Vallecito Station County Park, stopping where we saw patches of green from recent plant growth, or where we saw flowers. We saw over 1,000 plants in bloom of at least 40 species; see the list using scientific names, or the list using common names.

Fig. 1 shows two of the showiest species we found in bloom, Proboscidea althaeifolia, desert unicorn plant; and Senna covesii, desert senna.

Unfortunately, biting bugs, perhaps "no-see-ums" since the bugs themselves were not obvious, were also present in most of these locations, as well as some annoying bugs in places that had to be hand-waved away repeatedly. Tom received at least nine bites that produced angry red bumps the next day, mostly in areas under my t-shirt and shorts. Nancy reported a similar number of bites, despite wearing long sleeves and long pants. These bugs almost always accompany monsoonal annuals in bloom in our area.

We also observed a large area where essentially all the ocotillos had leafed out. See Fig. 2.

What was surprising is that the location with the highest reported rain total, 2.5 inches at Scissors Crossing on 10 August 2021, had zero annual germination! There was evidence of significant recent water flow there, so it is a mystery why no summer annuals germinated there so far. Also, four locations within the area where all the ocotillos had leafed out also had very poor annual germination.

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

Anza-Borrego Wildflowers Bloom Report by Fred Melgert and Carla Hoegen, often with daily wildflower updates.

All iNaturalist observations in the Borrego Desert since 1 August 2021 (click on "Filters" to change the dates; there were 67 observations of 36 species post as of 21 August 2021.)

Wildflower Updates from the Anza-Borrego Desert Natural History Association.

Anza-Borrego Desert State Park official site, with wildflower information on it. When they start producing current wildflower reports, click on the link near the top with the word Update, which might be updated weekly.

DesertUSA Anza-Borrego Desert State Park Wildflower Reports

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)

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Copyright © 2008-2021 by Tom Chester, Nancy Accola, Jim Roberts, and Birgit Knorr.
Commercial rights reserved. Permission is granted to reproduce any or all of this page for individual or non-profit institutional internal use as long as credit is given to us at this source:
Comments and feedback: Tom Chester
Updated 6 September 2021