August 5, 2016


Castilleja sp.
Orobanchaceae (Broomrape Family)

Quick ID
Castilleja blooms in early summer in a wild assortment of reds, oranges, pinks, yellows, even purples.  The colorfully painted brush atop each plant is not actually the flower, but rather the plant's leafy bracts that gradiate to green towards the base.  The actual flowers at the tips of these petal-like leaves are not much to speak of.  Paintbrush tends to be a moderately sized perennial herb, upright and with a woolly quality.  The narrow leaves  are alternately arranged, without stalks, clustered along a stem that can get woody at its base.  Castilleja could easily be confused with the closely related owl clover (Orthocarpus) or even the not-closely related Liatris, if one isn't careful.

Liatris (right) and owl clover above...both native, neither one a paintbrush!
At any rate, the species can be exceedingly difficult to tell apart, as they hybridize easily.  Even the most authoritative taxonomists in the business use caution with this genus.

Around 200 species of Castilleja evolved in the Americas and northern Asia.  Most of the diversity is found in the Northwest region of the US and Canada, although species range down to the Andes.  Plants grow in a wide range of ecosystems. Look for them in forest meadows, rarely in dense stands but instead sprinkled in among other wildflower communities.

What's in a Name?
One used to commonly hear this plant called Indian paintbrush (although most gardeners and botanists I know have come to find the term distasteful) or prairie-fire. The genus name Castilleja was first published in Carolus (the younger) Linnaeus's Supplementum Plantarum in 1782, after Professor of Botany Domingo Castillejo of Cadiz, Spain.  The name was chosen by Jose Celestino Mutis, a world-class botanist in his own right, who must have been one of Castillejo's admirers.  The surname, incidentally, means "little castle".

Around 2001, the botanical family Scrophulariaceae started to get a major makeover.  To put it simply, improved research methods started revealing that as far as genetic relationships are concerned, way too many plants were being included in the family.  So taxonomists kicked a whole bunch of genera out of the group, squeezing them in with Orobanchaceae, Plantaginaceae and some other families.  This sort of taxonomic restructuring can get really technical...and really messy.  Take, for example, the Wiki entry on Scrophulariaceae (which, admittedly, has always been something of a mishmash family) :
Fischer (2004) considered the family to consist of three subfamilies; AntirrhinoideaeGratioloideae, and Digitalidoideae. He further divided the Gratioloideae into five tribes; GratioleaeAngeloniaeaeStemodieaeLimoselleae and Lindernieae. He then divided the Gratioleae, with its sixteen genera (and about 182 species) into three subtribes; CaprarinaeDopatrinae and Gratiolinae. The Gratiolinae had ten genera (about 121 species) distributed through temperate and tropical America; Bacopa and Mecardonia (formerly Herpestis), Amphianthus,GratiolaSophronanthe,  BenjaminiaScopariaBoelkeaMaeviella and Braunblequetia. Many of these were transferred to the family Plantaginaceae, in the tribe Gratioleae.
 Yikes!  While some folks, bless their hearts, really get excited with this level of nit-picky detail, the rest of us are left throwing our forever-outdated field guides up in the air, exasperated.   What's cool about the binomial nomenclature system (Genus species) is that everybody all over the world can use the same name for an organism, no matter what language you speak or what region you hail from.  Nice and simple.  All the new (yes yes, more accurate) swip-swapping of names can get complicated, and intimidating for the budding botanist.
At any rate Castilleja, formerly a scroph, is now in the Orobanchaceae (Broomrape) family.  This actually does make sense, as the broomrapes, like paintbrush, are largely parasitic plants.


Castilleja is what's known as a hemiparasite.  Unlike true parasitic plants, it has the chlorophyll to photosynthesize on its own.  It can even live on its own, but will be stunted and miserable.  It would much prefer to worm its haustoria (special roots for plants looking to borrow a bit from their neighbor) into their host plant's root system and pick up a little water- and nutrient-boost.  I thought Tracey Switek's post in The Olive Tree explained it really nicely, so give it a look-see to learn more about paintbrush's fascinating parasitism.

And before you cast it aside as a thieving rascal, take heart in the benefits the paintbrush brings to its environment.  Besides the utterly lovely burst of color it provides, this is an excellent pollinator plant, full of nectar and visited by all manner of bees and hummingbirds.  It's also an important larval host for Schinia moths and checkerspot (Euphydryas) butterflies.  The flowers are theoretically edible for people too, and have historically been used to treat various ailments (including love-sickness).  The plant's tendency to accumulate potentially-toxic levels of selenium in the leaves, however, means would-be foragers should go forth with caution.

Wild Gardening
Because paintbrush naturally grows in complex relationship with other plant communities, it's notoriously difficult to cultivate in the garden.  But not impossible!  Collect seed capsules midsummer to fall and dry them in paper bags.  Try giving the seeds a month or so of cold moist stratification...different species will respond to this treatment differently.  You could also try sowing seeds outdoors in fall so they're exposed to naturally fluctuating temperatures.  Start spring seeds in pots or again, try sowing them straight into the ground.  You should see germination within a couple weeks.  A host plant is not required to get seeds to germinate, but your paintbrushes will languish soon without.  Your best bet is to grow it near other native plants that it would be found alongside in nature.  Time to start building that native wildflower meadow you've always wanted!  Good luck!

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