The second week of May, my husband Bill and I made our usual spring hike to see how things were going in the oak woodland section of Shell Ridge Open Space in Walnut Creek. It’s one of the things we do as board members of the Walnut Creek Open Space Foundation. (The foundation partners with the City of Walnut Creek to do stewardship and education in the open space, which is owned by the city.) We walked along the Costanoan and Upper Buck trails plus some of the Lower Buck.
The first noteworthy thing we came across was the largest single owl’s clover plant (Castilleja exserta) I have ever seen. Many of the blooms on neighboring plants were an unusually dark, intense color, which unfortunately the camera didn’t capture properly. However, it did a good job with the winecup clarkia (Clarkia purpurea). We’re almost sure the blue-flowered plant is ookow (Dichelostemma congestum), but it would be just as pretty by any other name. We didn’t see any others like it.
Yellow mariposa lily
Next we went around the corner to check out the meadow that had lots of yellow mariposa lilies (Calochortus luteus) last year. There were lots again this year. We saw three or four hillsides with calochortus dotted all over. We had heard that C. luteus had a white morph, and we saw several examples of this, along with some flowers of intermediate coloration. The obvious alternative explanation for white flowers is that they’re yellow ones faded with age, but judging by our close-up photos, that is not the case here. We often see black beetles inside the flowers.
Clarkia and Brodiaea
Elegant clarkia (Clarkia unguiculata) is always common along this trail, but this year it was so plentiful it made curtains of pink mist. Parts of the same area had a lot of harvest brodiaea (Brodiaea elegans), a plant we had never seen in Shell Ridge before.
The last unexpected thing we saw was large patches of Ithuriel’s spear (Triteleia laxa)—many more plants than usual on both sides of the trail. If you’ve done much hiking, you’ve probably noticed that the flowers always seem to grow on the hillside above the trail. Rarely do we see any flowers below the trail, at least not below the immediate shoulder. But here there were many below the trail we were on, not only more Ithuriel’s spear, but elegant clarkia and even some soaproot (Chlorogalum pomeridianum), which is out of sight in the photo. We complimented Walnut Creek Open Space staff on all the flowers and asked what was different. They said they tried to weed whack around the flowers. We were delighted.
About a week later, I was in the Twin Ponds area, another woodsy location in Shell Ridge. I observed the same pattern of more flowers there this year, but with some differences. The first group of unusual flowers was a different calochortus species, clay mariposa lily (Calochortus argillosus). There were several nice patches of about 30 plants each. Note the pointed green seed pods sticking up by the flowers. Normally most, even all, of the seed pods are eaten long before they ripen, usually by deer.
Once again, there was a large amount of harvest brodiaea, including a group of about 40 plants.
There were also several large groups of Ithuriel’s spear.
Partway up the trail, some hikers asked whether I knew if the cattle were coming this year, and suddenly I realized their absence might explain all these wonderful flowers. This land has been lightly grazed for decades; is that suppressing the bloom? Did the absence of cattle have something to do with all the flowers we saw on our earlier walk? Or was it the unusual rain pattern this year? I don’t know the answer, but it’s something to ponder as we all try to figure out how best to manage our land and keep the ecosystem functioning.
— Text by Lesley Hunt, photos by Bill and Lesley Hunt, Walnut Creek Open Space Foundation