Compare with Lactuca serriola, Prickly Lettuce. Here is a link that might be useful:

I have a north facing hillside that I'd prefer to not have to weed. Bermuda grass and sheep sorrel (two really horrible rhizome spreading nightmares) are endemic in my neighborhood. So I've planted all tough plants that can compete back, and with each other. Some posters complain about rudbeckia black eyed Susans being invasive, but mine are struggling against the evening primrose and Bermuda grass: This was in May, when the primrose was all in bloom. Now daisies and echinacea are blooming, and they are too large to go down in the sea of invasives. The grasses as well are quite tough and hold their own. Gaura is the one plant I wish I could get to thrive here, but it's had trouble. Summer heat and drought tends to beat down the smaller invasives and lets the larger, tough grasses and coneflowers and daisies cement their place. I've released mint on this hill, as we churn through the fresh herb for cooking, but it has had trouble taking off. A month later, the beginnings of the echinacea flowers:

All are good tips to deal with Field Bindweed (a.k.a. Morning Glory). Here's my 2cents worth: The most effective way to deal with any plant (either to make it grow or to kill it) is to understand how it propagates itself. One of the reasons that Bindweed is so invasive (and frustrating) is that it really badly wants to "go forth and multiply". Bindweed is very successful at all of the requirements for survival: 1)It's a long-lived perennial, 2) it propagates both by vegetation and by seed 3)the seeds are viable for a long time in the soil (I've heard 30 years) 4) I've seen a picture of the root system being over 20 feet deep 5) it will re-sprout a new plant at each "node" along the root and stem 6)it's quite drought tolerant 7) it is happy in ANY kind of soil (clay, sand, rocks, loam... But it likes disrupted soil the best. All this is very discouraging, but understanding Bindweed's method of reproduction helps control it. Here's what's been successful for me in "managing" Bindweed in my yard, and in the other yards that I've worked in. I've delt with many acres of Bindweed, and now only have to carry a small bottle of glyphosate in the spring and remind the Bindweed who's boss. ;) 1) First line of attack is to manage the existing plants, and their root systems that sprout from each node when you pull off the top. I've tried many ways to deal with the "parent" plant (pulling, smothering, tilling, burning, vinegar, salt, solarizing with plastic, etc.). But the most effective way that I've found is that it's important to use an herbicide that trans-locates the herbicide through the root system (therefore killing the roots along with the vegetative top growth; remember that Bindweed sprouts from each node including on the root system). Glyphosate (the effective ingredient in Roundup) is one of the more successful herbicides that trans-locates through the root system. There are a few "tricks" in using glyphosate. Follow the manufacturer's instructions and mix the glyphosate using the instructions for "shrubs/vines" (in other words, mix it as strong as possible). Glyphosate is easily neutralized by contaminates, so make sure you don't use dirty water (from a pond, etc.), don't add any other chemical unless it specifies that it's compatable, and make sure that you don't use a metal canister to mix/spray/store it in (I use plastic). Having said that, I add a few "secret ingredients". Glyphosate works best in slightly acid pH water. Most of our mountain states have alkaline soils, and therefore alkaline water. Therefore, I add a bit of vinegar (about a tablespoon/gal) to acidify the water. The next ingredient that I add is a surfactant (which some of the herbicides already have in them). A surfactant breaks down the surface tension on the leaf, and allows the herbicide to spread over the surface therefore being more available to be absorbed (also called a spreader/sticker). One of the easiest surfactants is liquid dish soap. A few drops is plenty. The final "secret" ingredient is a bit of water-soluble fertilizer such as Miracle Grow. It is extremely important for the plant that you want to kill is "actively green and growing". Fertilizer helps with this. Keep in mind that glyphosate is a NON SELECTIVE herbicide. It will kill any plant, but it has to touch the leaves (or other part of the plant that has chlorophyll in it (some plants have chlorophyll in their trunks/stems). Glyphosate is neutralized in the soil and therefore is NOT a soil contaminate/sterilizer. Be careful of chemical drift (the wind blowing the spray to other plants), tracking glyphosate on your shoes, tracking via pets, rain, etc. If the Bindweed is amoung other plants, I use a plastic drinking cup that has the bottom cut out. I pull the Bindweed through the bottom of the cup, and then spray into the cup therefore reducing the possibility of the herbicide drifting onto other plants. I let this dry, and then remove the cup. I also have heard of using a paint brush and painting the leaves, and also "foaming" the soap into bubbles (remember the soap?) and placing the glyphosate-infused bubbles on the plant. It's hard to be exact when you're spraying, so try these other options. It is most effective to use glyphosate in the fall when the plant is pulling nutrients into their roots getting ready for winter. But, Bindweed takes persistence, so use it whenever you can. Another tip: DON'T use any herbicide when the temps. will be over 80degrees!!! Most all chemical herbicides will volatilize above 80 degrees and turn into a gas and drift onto other plants. :( 2) Now we have to deal with the seeds! A pre-emergent herbicide (such as Preen) will help, but you're only putting off the germination of a 30 year viable seed. I've chosen to allow them to germinate and then continue to kill the "parent" plant. Do this by pulling new seedlings and continuing to use glyphosate to kill the more mature plants. Remember, each time you till or work the soil, you're bringing up seeds to the surface so that they will germinate. It will seem like a never-ending battle, but you can win! There's an old saying that it takes 7 years to manage one year's worth of laziness by allowing a plant to reseed. Don't give up! Sorry for the long reply. Hope this helps!

I'm not good with specific names of weeds, but I do recognize number 3 as a dandelion. The last one I have in my yard. Those yellow flowers will turn into puff balls of seed that fly everywhere. You don't have time to spray those away. Get a shovel and cut them off at the base before the flowers become puff balls. The first two I'm going to classify as wildflowers. It's great that you seeded your lawn in the fall. We talk for what seems like hours about the problems with spring seeding, one of those being that in the spring you also germinate the summer weed seeds. Well when you seed in the fall you are also germinating the spring wildflower seeds. Those plants take root but only barely. They remain dormant until spring when they bolt and become a flowering plant. They send up flower spikes quickly, flower, and then die away. The seed remains on the surface waiting for perfect circumstances in the fall when they will germinate again. The good news is that you can almost always control the circumstances so that they will not germinate. One way you could have changed this outcome would have been to RoundUp once last fall, then water daily as if you were sprouting grass seed. This frequent watering would have sprouted these spring wildflower plants. Then a week later you would spray a second time with RoundUp to kill all the newly sprouted weeds. Then you could clear the surface, sow the seed, roll it down, and begin watering your new seed. But here we are in the spring and you have weeds before you have grass. This happens to everyone every year, so don't get panicky. Weed-B-Gone spray should take care of these weeds and leave the grass alone. Don't listen to the TV when deciding when to fertilize in the spring. Your grass will awaken from dormancy and shoot out of the ground like crazy grass. What you need to do then is hold your horses until the grass growth slows back down to normal. There is no need to fertilize early but there is a need to fertilize later, after the growth slows. Usually Memorial Day is a good time to do your spring fertilizer. By then everyone's grass should have slowed down. If you fertilize early you force the plant to use resources which were supposed to last it much longer. Then the grass falls into poor health until next spring. If you want to do something for your grass and soil now (or any time) you could apply an organic fertilizer. Organic fertilizers act differently from synthetic fertilizers. They are a biological product which feeds the soil microbes. Once those microbes are well fed, they improve the overall health of your soil. Feeding the plants is more like a byproduct of improving your soil's health. Since the two types of fertilizer work differently, you can apply both on the same day without any fear of interaction.