Bladderpod (Isomeris arborea) and rattlesnake grass (Brisa maxima)

Question from Christine:
found plant with off white seed pods
sound like a rattlesnake when the wind
blows – west area of mission trails park

Answer from Pat:
I think you found Bladderpod (Isomeris arborea) Its inflated dry seed pods in fall and winter sound a little like rattlesnakes when they blow in the wind or when a hiker brushes against them. It is a highly drought-resistant native shrub that bears yellow flowers through a long season of winter and spring. The Indians ate the flowers after boiling them for four hours. They ate the seedpods and seeds also which are said to taste like capers. The seeds are loose inside the pods which is why they rattle.

There is another plant called rattlesnake grass or quaking grass (Brisa maxima). There are some other brisa species also that are smaller than Brisa maxima. It’s a very attractive grass used in flower arrangements and the ripe seedpods sound like rattlesnakes if you brush through a field of them, but it’s a non-native from Europe and dangerously invasive. Invasive plants like this one can crowd out native plants. Unfortunately, brisa grasses are already naturalized through much of western USA. I would think that volunteers and docents would be pulling out and destroying rattlesnake grass if they found it growing in Mission Trails Park Reserve.