Various species of Phacelia are fire-followers and have bloomed in profusion in areas burned by the Station Fire. These are Davidson’s Phacelia (Phacelia davidsonii) along the Three Points – Mt. Waterman Trail about a mile from Three Points.
Like Turricula (Poodle-dog bush)*, many species of Phacelia can cause a contact dermatitis similar to poison oak. Generally, any Phacelia should be considered suspect, and especially those that are fuzzy and sticky.
One Phacelia that has been shown to elicit a reaction is California bluebell (Phacelia minor) — a relatively common wildflower in the middle to lower elevation areas burned by the Station Fire. In one study, it was found that the amount of two active compounds in Phacelia minor required to produce a qualified reaction was 6.3 µg and 3.8 µg; compared to 170 µg for Turricula and 1.6 µg for a component of urushiol from poison ivy.
*The taxonomic name for Turricula parryi (Poodle-dog bush) has changed to Eriodictyon parryi. The Jepson Manual: Vascular Plants of California, Second Edition (2012) has returned Turricula to the genus Eriodictyon, as originally described by Gray. According to the Wikipedia entry for Turricula (April 11, 2012), “… molecular phylogenetic analysis carried out by Ferguson (1998) confirms that Turricula should be treated as a separate genus within a clade (Ferguson does not use the term “subfamily”) that includes Eriodictyon, and also the genera Nama and Wigandia; Eriodictyon is the genus to which Turricula is closest in molecular terms, and is its sister taxon.” I use “Turricula” and “Poodle-dog bush” interchangeably as a common name.
Poodle-dog bush Along the Silver Moccasin Trail at Shortcut Saddle
I knew Poodle-dog bush* was a common fire follower, but had never run or hiked through a burn area where it was abundant. Wow, it was everywhere on the Red Box – Bear Canyon – Gabrielino Loop last Saturday, and particularly dense on sections of the Gabrielino Trail between Switzers and Red Box. It appears to be one of the most common fire-followers in the Station Fire burn area, and likely plays an important role in the recovery process.
Gland-tipped hairs on Poodle-dog bush leaves. Click for larger image.
Gland-tipped hairs on the plant secrete a sticky substance that causes a rash “like poison oak” in sensitized persons. I thought I wasn’t sensitive to the plant, because I had brushed against the leaves of Poodle-dog bush before without reacting to it. This time my exposure was repeated, frequent, and prolonged; and the leaves were heavily coated with exudate. At the end of the loop my legs and forearms were coated with a thick layer of resinous brown gunk that would not wash off with water.
Trail dust and other debris caught on a sticky Poodle-dog bush leaf. Click for larger image.
By the time I had finished the run, talked to some people at Red Box, and driven home, 2-3 hours had passed. Tecnu helped remove the resinous goo, but as I would discover a couple of days later, it did not prevent me from getting the rash.
My reaction to Poodle-dog bush was quite a bit different than what I’ve experienced with poison oak. A blotchy red rash developed on my arms and legs Monday, about 48 hours after exposure. After another 24 hours I thought the rash was going away, but it was actually morphing into a more widespread and uniform inflammation that was similar to bad sunburn — a very itchy sunburn. There was some swelling and edema, particularly on my ankles. In the areas that had the most contact with the Poodle-dog bush, primarily my shins and around my knees, there was some blistering. The blisters were small, perhaps 1/16 inch in diameter or less.
Flowers of Poodle-dog Bush near Three Points
Most of the blisters were gone by Thursday afternoon, and since then the inflammation has been slowly subsiding. Although very itchy and annoying at times, it has not been debilitating. An equivalent exposure to poison oak would have been much more severe. However, in my case an underlying irritation or sensitivity has lingered for some time after the visible reaction dissipated. It seems like it will probably take a few more days for the reaction to completely resolve. We’ll see!
Update July 12, 2011. My reaction to Poodle-dog bush cleared after about two weeks. A running friend who recently did some trail work removing Turricula on the Kenyon Devore Trail sent this photograph of a blotchy red rash that developed on his forearm. He first noticed a reaction four days after doing the trail work, and the photograph was taken 10 days after exposure. As in my case, several hours later he commented that the blotchy rash had merged into a more general inflammation with swelling.
Poodle-dog bush leaf arrangement
Research has found the dermatitic agents in the Poodle-dog bush exudate are “phacelioids,” hydroquinone based compounds structurally related to poison oak/ivy urushiols, but not as active. In one study the amount of the phacelioids in Poodle-dog bush required to produce a qualified reaction was 100 times that required for a component of urushiol from poison ivy — 170 µg vs 1.6 µg.
It is also noted that in place oxidation of hydroquinone based phacelioids is likely necessary to interact with the proteins of the skin and produce a reaction. This (and common sense) suggests that leaving the Poodle-dog bush exudate on your skin for several hours (like I did) is probably a bad idea.
The book Poisonous plants of California by Thomas C. Fuller, Elizabeth May McClintock (1986) describes a 1941 incident in which hairs from old flowering stalks “easily broken from the stems” caused a rash, but flowering plants the previous year did not.
*The taxonomic name for Turricula parryi (Poodle-dog bush) has changed to Eriodictyon parryi. The Jepson Manual: Vascular Plants of California, Second Edition (2012) has returned Turricula to the genus Eriodictyon, as originally described by Gray. According to the Wikipedia entry for Turricula (April 11, 2012), “… molecular phylogenetic analysis carried out by Ferguson (1998) confirms that Turricula should be treated as a separate genus within a clade (Ferguson does not use the term “subfamily”) that includes Eriodictyon, and also the genera Nama and Wigandia; Eriodictyon is the genus to which Turricula is closest in molecular terms, and is its sister taxon.” I use “Turricula” and “Poodle-dog bush” interchangeably as a common name.
Some invasive plants, such as this milk thistle (Silybum marianum) on the Phantom Trail in Malibu Creek State Park, appear to respond disproportionately to above average rainfall and become particularly large and prolific.
Saturday, I’d run in the Malibu Creek Challenge 22K. Today I Wanted to do something low key. Not too long, not too steep, but still a run that would work out the kinks that follow a race. I finally settled on the Secret Trail to Calabasas Peak, a 4.25 mile course with an elevation gain/loss of around 750 ft.
The low clouds and fog that surged into the Santa Monica Mountains on Saturday had returned during the night. The mustard and monkeyflower along the trail were soaked with dew, and now, so was I. Running felt good, and the two or so miles to the peak passed quickly.
The sun had nearly burned through the morning overcast, and just below the summit of Calabasas Peak, the bright yellow flowers of a Spanish broom seemed to capture and concentrate the subdued sunlight.
Spanish broom (Spartium junceum) is a twiggy, green shrub that originated in the Mediterranean. It is common at lower elevations of our local mountains. According to the California Invasive Plant Council it was introduced as an ornamental in San Francisco in 1848, and planted along highways in Southern California in the 1930s. Its color and fragrance are distinctive.
Prior to running the Inca Trail we did an acclimatization run at 11,000 ft on the altiplano near Chinchero. The very first flower I saw on the run was a Spanish broom! This suggests that Spanish broom could spread to higher elevations of the San Gabriel Mountains, particularly if climate change results in more arid conditions.
As we’ve seen this Winter, it is the norm for Southern California’s weather to be abnormal. Cool, wet weather in December was followed by weeks of warm, dry weather in January. It is hard to predict when it will be wet and when it will be dry. Especially if you are a plant.
This photograph of a shooting star (Dodecatheon clevelandii ssp. patulum) is from early February, when the weather was dry. Droplets of moisture can be seen clinging to the interior walls of the seed capsules. These climate moderated capsules helps ensure that the plant will produce viable seeds, even if an extended period of dry weather should occur after the plant blooms.
