The area near the Mission has several kapok trees as part of the standard landscaping. These trees are peculiar in that they are spiny when young, so their trunks look like wooden durians. Once they hit twenty or so, they start to fruit. A large, heavy husk like a wood avocado opens up to reveal light fluff containing seeds. The fluff blows away.
When I was little, kapok was the common stuffing for plush toys. Natural, renewable, biodegradable - now kapok just blows away in the wind and we use polyester batting made from oil in our toys instead.
Kapok blowing in the Santa Ana wind over San Juan Capistrano.
Their latin name is Ceiba pentandra and they are originally from Mexico. Known as Ya'axche, they were sacred world trees to the Maya.
Here's most mature tree, at the foot of the hill by Las Brisas:
And here's a close up of the thorny bark (starting to lose its thorns
now it's mature) and random kapok: