Pacific poison-oak
Toxicodendron diversilobum

Anacardiaceae

The song birds really loved flitting through the dried poison-oak. I couldn't tell what they were or if they were picking at the seeds. Since I don't carry binoculars with me on hikes (sheesh, I can barely tolerate carrying my point-and-shoot), I wasn't about to get closer for a better look.

For anyone who enjoys outdoor activities in California, it's a good idea to learn to recognize poison-oak throughout its many seasonal variations. Click my previous poison-oak posts for more pictures and information. Even the bare winter twigs can cause a rash in many people. And as my husband learned the hard way, animals that run through the brush can collect the rash-inducing oil on their coats. He helped a lost dog named Lola on December 8, 2010 and even now still has poison-oak rash scars. While I love dogs, especially ones that don't jump on me and knock me over, I will go to great lengths to avoid touching any dogs I meet on trails.

ps - I'm starting to use an alternative common naming convention for plants, where if the last noun is not the actual thing, then I hyphenate. Pacific poison-oak is not a true oak, like coast Douglas-fir is not a true fir. I've also seen poisonoak as one word. To read my rant on common naming conventions, see my bat star post. If anyone has any thoughts on this, I'd love to hear from you.

Pacific poison-oak
Toxicodendron diversilobum

Anacardiaceae

If nothing else, California's ubiquitous poison-oak serves as a beautiful autumn (and spring) color addition. Our local black-tailed deer supposedly eat poison-oak. For more information, check out the embedded links I've provided above, or check out my previous poison-oak posts.

If you asked my husband, who is an avid trail runner (always wearing shorts with exposed legs, I might add), I'm guessing he'd say poison-oak and yellowjackets are the two worst things about California. He was born in SLO here in CA but was raised in Canada and Washington state. While trail running, he'd prefer the immediate pain of blackberries, as is found plenty in WA, versus the 1 day to 2 weeks delay of the onset of the poison oak rash. He questions the evolutionary advantages of a defensive mechanism that comes out weeks after exposure. We know friends who have gotten the rash on private parts (er, I didn't really want to ask for more details) and boys who seem to like rolling around in it as a last ditch effort to avoid going to school for a week. Many local parks and reserves have prominent signs warning about touching the poison-oak, even the bare winter twigs. If you're not familiar with it, it can be challenging to identify based on a very common 3 leaf configuration. Not everyone experiences the same kind of rash, if at all. I'll admit, I've never experienced the "fun" that is poison-oak, poison ivy, or poison sumac... and I'm a little fearful my boasts may do me in, so I'm careful around the stuff.

poison oak ~ 08/04/10 ~ Fort Ord

Pacific poison-oak
Toxicodendron diversilobum

Anacardiaceae

posted 08/14/11 - Always trying for better photos. Am working on this day's hike from last year, because I just had a spider ID'd by an expert.

ps 07/10/14 - Caltrain asked permission to use the 3rd picture above in a video "Caltrain 150th Documentary - The San Francisco and San Jose Railroad".  Cool.

Pacific poison-oak
Toxicodendron diversilobum
Anacardiaceae

I've also seen this species called Rhus diversiloba, but regardless of the scientific name they both refer to the poison-oak found on the Pacific coast. See links from any poison-oak indexed post for more information.

Our local poison-oak is remarkably red right now and stands out against the dried grasses.

Coincidentally, my husband's poison-oak rash had just started coming out the night before from, we assume, the previous weekend's camping adventure without showers. Usually after trail running, he washes immediately with tecnu, and if he does get a rash it is very minor. I credit my almost always wearing long pants when I go hiking to never having gotten poison-oak. Knock on wood!

The rash initially looks like individualized, raised red bumps less than a cm in diameter. Since this was a very bad rash, it looked like he had been stung about 50 times on the back of one leg. He says it feels just as itchy as a yellowjacket sting, but without the initial sting and lasting much longer.

ps - By the Monday after this post, the rash had turned very bright red and started oozing (very gross!). We purchased the over-the-counter Zanfel for over $40 for a 1 oz. tube (very expensive stuff). It's a tedious process of repeated applications and washing, but he claims it helps with the itching better than 1% hydrocortisone cream.

pss - It's now been 10 days since the rash first came out. It's dried up a bit and the red has spread outwardly from the initial bumps. He says it has finally stopped itching. Not fun!

Pacific poison-oak
Toxicodendron diversilobumv
Anacardiaceae

Very green poison-oak with seed pods.

Pacific poison-oak
Toxicodendron diversilobum
Anacardiaceae

Very green poison-oak with flowers.

Pacific poison-oak
Toxicodendron diversilobum
Anacardiaceae

Poison-oak really is quite showy and beautiful. I'd wear shorts and water sandals more often for my hikes if it wasn't so ubiquitous. Thank goodness I'm not familiar with the "fun" of the allergic rash. I've skinny-dipped in poison ivy-infested areas and trudged chest-deep in sumac-infested bog waters and have never gotten a rash. Knock on wood!!!