Over the years I have occasionally found small sunflowers popping up in my yard in pine cove and elsewhere on the hill. These are wimpy plants that never seem to mature and produce seed, so I attributed them to seeds from my bird feeders.
This year I began to notice some plants around Idyllwild that I could not identify that looked like miniature corn stalks, so I wondered if they came from corn from squirrel feeders. Recently I found some of these plants that had produced seeds revealing clues to their identities.
Three components of bird seed are sunflower, millet, and milo (sorghum). Many of these field crop cultivars are hybrids and/or genetically engineered, so they may not key out precisely in the floras.
Sunflower and millet on Morris Ranch Road above Garner Valley found growing with sorghum:
Sorghum on Highway 243 between Jameson and Point of Rocks roads found growing with millet:
All three are annuals. We have some native sunflowers on the mountain, but they almost always appear as much more robust plants than these escapees from the bird feeders. Both millet and sorghum prefer warm temperatures which is probably why they do not proliferate on the mountain. We have never seen them in wilderness areas. nonetheless, if you find any of these plants in your yard it would probably be a good idea to pull them up or at least remove the seed heads. as a bonus you can recycle the seeds by putting them back into your bird feeders.