The first seedling with the "forked-tongue" cotyledons is a native California poppy. Notice the overall glaucous cast (flat, whitish film on surface like on a cabbage leaf) to the leaves and stems, the multiple fine divisions and pink tips of the true leaves and how these same traits are just starting to uncurl and show in the seedling.
California poppies have minuscule seeds (1.5-1.8 mm) that are flung out of a long pod as it dries and splits. These seeds probably settle under bits of litter and into soil cracks where they are soaked by the first rains. California poppies are perennials that also come back from a taproot. If you see the forked cotyledons, however, you know that plant germinated from seed.
The second seedling with the prickly true leaves is a weedy thistle not native to California, probably Italian thistle because of the fine white prickles on the upper surface of the blade. Look at the side-by-side slightly older thistle seedlings above. The seedling on the left has fine long white hairs on the upper surface (Italian thistle) and the seedling on the right has no such hairs but large white splashes cross from the center vein to the edge of the blade and often alongside the leaf veins (milk thistle).
The third seedling with the corkscrew seed pods is a filaree, probably red-stem filaree which is found in grasslands, pastures and yards and is not native to California. The corkscrew attachment to the seed expands and contracts with moisture and effectively screws the seed into the ground. The previous photo showed the spent attachment with the seed already detached.
More seedling photos coming up. And one other note: I saw a few coast range newts crossing Alpine Road this evening, so look sharp when you are driving the next few weeks on or after rainy or foggy weather.
--- "I better get moving to the ponds before all these seedlings grow up and get in my way. Monocot, dicot, out of my way. ---
California poppy, Eschscholzia californica
Italian thistle, Carduus pycnocephalus
red-stem filaree, Erodium cicutarium