Still flowering at this time of year, the flamboyant Indian paintbrush, Castilleja coccinea (also seeds can be collected) has one of the best common names given to a wildflower – someone must have watched the colourful leafy bracts reflecting red-orange paint strokes over the blue sky!
Castilleja coccinea – Indian paintbrush
Many species with seeds adapted for wind dispersal have various helping ‘devices’ (wings, hairs…). In the case of Castilleja, the seeds have a honeycomb outerlayer – nature’s design for helping with the process. The honeycomb pattern is produced by dead, air-filled cells of the single-layered seed coat.
Castilleja coccinea seeds (This is as close I could get with my camera and please ignore the debris)
Castilleja and few other Orobanchaceae present the most impressive variation of honeycomb-patterned seed coat, where both the outer and inner tangential walls are dissolved and all that remains is a loose honeycomb ‘cage’.
About the germination:
I intend to include Castilleja in a small flower meadow, so I gather info and I shall experiment. The difficulty is to start a small population because like other hemiparasitic plants it needs its host plants to help it grow. Mostly behaves as a biennial, and in most cases if successful, it will reseed around.
Various studies had shown that C. coccinea will establish connections with the roots of a wide range of host species. It will germinate by itself but it won’t establish and grow well without a host. The best method is to sow it outdoors in the fall or spring in an area where few preferred plant host are growing (most common: little bluestem, prairie smoke, grama grass…) or in pots in combination with seeds/young seedlings of the host plants (use peat or coco-fiber pots as it dislikes transplanting).
Also, other essentials factors for good germination and survival are good moisture and surface sowing (light sensitive).
I showed at some point another beautiful Castilleja, C. applegatei var. viscida in a mountain meadow from the Wasatch Mountains.
Update after quite a few years: I once managed to have seeds germinated in a container outdoors, but the seedlings perished, in part to the squirrels digging them up.
Second attempt: a bunch of seedlings showed up after I spread a large amount of seeds into the ground (2022). I will watch with interest what happens in 2023!
Castilleja coccinea seedlings, direct sowing on the ground in late fall
And success in 2023!!!
Other Castilleja species I managed to germinate is Castilleja applegatei, sowed in late fall and provided cold/moist stratification outdoors. The seedlings vanished at some point; it may have been too much or not enough watering, hard to say. So, unfortunately I cannot add more about seedlings development.
There are also seedlings of Castilleja miniata, also germinated after cold/moist stratification.
I am sure this story will have other developments in the next years!
