Southern California
Blueberries that turn into half pinecone flowers?
You don’t want to eat those “blueberries.”
It’s a species of Thuja (arborvitae, red cedar), a conifer.
There are a number of species of Thuja (some of which have been transferred to other genera like Platycladus. One is native to California, Thuja occidentalis (Western Red Cedar, Western Arborvitae, and other names), but neither the leaves nor fruits are right for it. Several species and cultivars of Thuja are popular ornamentals. Where is this tree, in a forest or a city planting?
Desert, out in the brush.
Your identification lead me to juniper berries. Those looked more similar in the photos to what I saw than the photos of thuja berries, which seemed to be less round and more mottled in color.
You don’t think it’s juniper?
Hmm. Actually it could be a juniper. But juniper berries don’t normally open into cones. It could be some kind of gall.
Juniper berries are technically cones, with the scales very fleshy and merged together to form a berry-like fruit. If that’s a juniper, it could be some kind of bizarre mutation or infection.
Are there many plants with cones like that, or just one?
The tree had a pile of perfect little blueberries under it. The one cone in the photo was the only non-blueberry on the tree. I found one or two more on the ground. Percentage-wise, cones were vastly outnumbered by berries.
California Juniper?
I think that’s still abnormal. California Juniper is mostly dioecious, that is, having separate sexes in each plant. Female plants have berries, male plants have small pollen-producing cones. A few plants are monoecious, producing both berries and cones. But I think these berry-cones are the result of some kind of developmental abnormality or infection.
The stems/foliage look very much like Juniper; the normal berries look like Juniper. I think Colibri is correct - this is Juniper where something has gone wrong with the formation of the berry - it’s interesting; almost like a throwback to what the more-recognisably conelike fruits of Juniper’s ancestors might have looked like