Plant Species of the Borrego Desert:Fabaceae:
Calliandra eriophylla, pink fairy duster
Calliandra eriophylla, pink fairy duster
Geographic Distribution
Photos from Smuggler Canyon by Franz Boschiero and Larry Hendrickson
Photos of Visitor Center Plant of Calliandra californica, a Baja sister species
Geographic Distribution
Calliandra eriophylla, with the delightful common name of pink fairy duster, is a rare plant in ABDSP, having been found in only three locations in San Diego County. Fig. 1 shows the reported locations.
Fig. 1. The three reported locations of Calliandra eriophylla in San Diego County. The two locations with accurate positions are shown with filled red circles, with an estimate of the size of each population. One other population, seen only in 1937, is shown as being somewhere inside the red area with question marks inside, and no estimate of the population size was given. The blue lines are county borders. The edge of the Salton Sea is at the extreme upper right.
The three populations are:
- Starfish Cove, in Alma Canyon above the Elephant Tree Natural Area, southwest of Ocotillo Wells, discovered by Jon Rebman and Larry Hendrickson on 24 March 2000. This population consists of just 23 plants in a single spot.
- Smuggler Canyon, Vallecito Mountains, sw of Whale Peak. This population was discovered by Florence Youngberg in 1936, and rediscovered by Franz Boschiero on 22 April 2005 (vouchered by Larry Hendrickson and Franz Boschiero on 23 April 2005). See Fig. 2 for photographs of these two discoverers.
Fig. 2. Left: Florence Youngberg in 1932, from the 1932 SDSU Yearbook. Right: Franz Boschiero in 2005.
Until we compiled the species distribution information for this page, it was not realized that these two vouchers were of the same population due to confusion about the 1936 locality; see Historical Confusion about Blair Valley, Pinyon Mountain and Whale Peak. This population was said to span 50 acres in 1936, with one plant to about every 200 square feet. That density estimate probably applies only to the plant spacing in the densest clumps.
- Extreme northeast corner of the county, shown at upper right in Fig. 1, discovered by Frank Gander on 3 January 1937. No other information was given about the population. Bill Sullivan has made a handful of recent collecting trips there, as have Tom Chester and colleagues, without seeing this species there. But the northeast corner of the county is a large area, with many washlets where the Calliandra might be hiding, so our lack of re-finding the species there does not imply it isn't still there.
If anyone has ever seen this species in San Diego County at any place other than Smuggler Canyon and Starfish Cove, we would appreciate knowing about it.
The name pink fairy duster derives from its pink flowers, which look like little feather dusters that are just the right size to be used by fairies. Its cousin Calliandra californica has red flowers.
There is one plant of a sister species, Calliandra californica, in the ABDSP Visitor Center that we have admired regularly, but despite all the surveys we have done, we never came across Calliandra in the wild until 15 December 2013. Before then, we had botanized the areas of all three of the reported locations without finding this species. One of those locations, in Starfish Cove, contained just 23 plants in the population, and we probably just didn't go by them on our one time-limited hike there.
We finally met with success on 15 December 2013 in seeing the Smuggler Canyon population. They were easy to find from an accurate GPS location of these plants and because this species was one of the dominant plants at this location (they are the low shrubs with the dark red leaves; see also picture with scale). We estimated at the time, from only seeing the edge of the population, that there were easily at least 100 plants here. Our later survey, where we counted most of the plants, gave an estimated population of 700 to 800 plants.
The plants in San Diego County are at the extreme northwestern edge of the range of this species, which is mostly found in the southern half of Arizona and throughout the mainland of Mexico (see SEINet occurrence map). The largest population in California is in southeastern Imperial County near the Colorado River.
From the geographical distribution of this species, its distribution is probably limited by cold winter temperatures and by the amount of summer rainfall. In fact, when Larry Hendrickson saw the red dead-looking leaves of the plants here, he surmised that the plants had been frostbitten. Most of the leaves were red and wilted except for the more-protected leaves in the center of the plants near the ground.
See also the Jepson Manual Second Edition Treatment.
Photos from Smuggler Canyon by Franz Boschiero and Larry Hendrickson
Click on the pictures in this section for larger versions.
Franz Boschiero rediscovered the Smuggler Canyon population in the glorious year of 2005. The following picture, taken by Larry Hendrickson, shows him standing next to the plants on 23 April 2005:
Larry also contributed the following two pictures from 23 April 2005:
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Franz returned to this population five years later, in May 2010, and took the following photographs:
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For more pictures, see Calphotos and the SEINet page.
Photos of Visitor Center Plant of Calliandra californica, a Baja sister species
Although there are said to be two plants of Calliandra eriophylla planted at the ABDSP Visitor Center Garden, the specimen of Calliandra most likely to be seen by visitors is Calliandra californica, a similar Baja California species with red flowers. C. eriophylla has pink flowers.
Buds. | 
Buds opening. |
Fruit (seed pod) before dehiscing (opening). | 
Fruit after dehiscing. |
Flower. | (no picture for this spot) |
The pictures of the Visitor Center plant were taken by Kate Harper on 16 December 2013. The pictures linked in the text from Smuggler Canyon were taken by Tom Chester on 15 December 2013.
We thank Larry Hendrickson and Franz Boschiero for permission to reproduce their lovely photographs of the Smuggler Canyon population.