Lomatium triternatum
Besides L. ambiguum, which I covered a few days ago, the only other lomatium I had growing on the property when I moved here in 1991 (whoa... thirty years ago!) was this one. There was one in the north part of what was then just a weedy alfalfa field, and one in the south, and they must have been old because they were huge examples. At full bloom they were about three feet tall, and I have never gotten one to grow that tall since. Alas, they died about five years or so after I moved in, and at that point I had been oblivious about collecting their seeds and keeping it going, so... that was one of the sad stories.
I knew that they had grown here though, and this is a plant that you won't have any trouble finding in this area, so I started by collecting a little seed, and discovered that it was happy to grow anywhere I planted it. There was a spot by the side of the road, just off my usual commute into Pullman when I was teaching at WSU, where some weirdly-situated patch of ground that couldn't be farmed had a significant population of native plants, including tons of Nineleaf biscuitroot. For several years I would wait until the seed heads were dry, and gather a good bagful, and it was a major source for the drifts now forming in the prairie.
It continues to baffle me that unthinking destruction of the few unspoiled bits of native habitat around here still goes on. Last year, a mile east of me, road crews on the Idaho side of the border went through and "cleaned up" the drainage ditches with a serious herbicide. There are places where that might be an OK strategy--you know, a patch of Poison hemlock. Absolutely, spray it. There are problem areas, but there were stretches full of native plants, with no noxious weeds (and believe me, I know the noxious weeds around here). They killed 'em all and let God sort it out. I had spent years being so careful to only take a little plant here and there out of drainage ditches down the road because they were weirdly pristine above, but surely to die in the gravel beside the road, so those were the ones I transplanted. There are more stories to come of roadside rescues. Well, in this case, I should have taken everything because they killed all of it. On both North and South River Roads, but thank goodness, not on the Washington side (details here for any curious Palouse residents). And they took out fifty patches of buttercups, a bunch of glacier lilies--some beautiful slopes of native plants!--on South River Road.
My point is that, in spite of the tiny amount of native Palouse prairie that remains, people still are finding ways to destroy it, and so it was with my source for biscuitroot seed. I was saddened five years ago to see that whoever owned that land where I had collected that seed had hit it hard with 2,4-D, killing everything but the grass. Another Palouse prairie remnant gone. But that Nineleaf biscuitroot, at least, lives on in my prairie.