Pull them out. Looks like a weedy Solanum. Here is a link that might be useful: Solanum rostratum

I think there is now a legal requirement that herbicides and pesticides must break down after they are applied. So, chemicals such as DDT are no longer allowed. The process is called mineralization. Usually it is measured at the site of application; if it is applied to a lawn, the persistence of the chemical is measured in the soil where it was applied. The process of breaking down the chemicals is typically via bacteria, so the presence of organic material that is decomposing affects the rate of decomposition of the chemical. Composting will, of course, speed the breakdown of these sorts of chemicals. My compost takes about two years to complete. So it becomes a judgement call. If you are comfortable knowing that lawn chemicals are designed to break down via bacteria, then you might be ok with other people's grass clippings if you compost it for a couple of years. Obviously, if you use lawn chemicals on your own lawn, you will know when they were last applied. You might want to dispose of the grass clippings right after a chemical application.

I believe Corn Gluten is considered an organic pre-emergence. Emergence meaning when the plant from seed can be seen above ground. Specifically what Corn Gluten does is attack the plant's rectal when the seed coat softens, opens and the stored energy within the seed begins growth by bringing the rectal into its escape route into your soil. Corn Gluten carries with it a low level organic nitrogen percentage that nurtures the existing plants while serving as a pre-emergence product. The cost of this and several chemical ways to do pre-emergence has always been debated. My opinion is that all ways of using pre-emergence tactics is only a relatively short time period of less that excellent control anyway. The chemical companies have always paid the universities to come up with warped facts to satisfy the use of their poisons. For instance as stated above: half life is a relatively short period of time but soil life comes out to be about a year. Few stop to read, think and question. First these chemicals are non-degradable. Half life I guess means only half of it has been flushed by rain or watering from your use point and is on its way to your rivers, bays and oceans. Full life must mean your soil is again void of the chemical. That is a direct statement that everything you put on is now en-route to the oceans of the world. The enormous poison pits and zones in the oceans are known and growing. There is no other place for them to go except to enter the evaporation facts and become even stronger where they are. Severe weather may lift them and redeposit them to complete the journey once again back to the ocean pits. If you use and love sea salt now how do you feel it will be enjoyed in another million years? Back to our soils now stated to be full life with no measurable poison in the soil. What they do not test and will not tell you is how long your natural biological recovery will take. The realistic recovery may be five years or longer. Is there a point of no return? I do not think anyone knows. No part of the answer to that question is very nice. Would growing the grass at four inches and mulching the cuttings make better sense? Would spot treatment in the early recovery make more sense than wholesale broadcast of some poison? Do we really need golf course picture perfect homestead grasses? Could we as homeowners recycle those leaves and plant tops by mulching open soil? Could legumes become cover crops that rejuvenate? I'm sure most could do some of these things to eliminate the use of some if not all man made chemicals. This reasoning and these questions apply to all man made non-biodegradable poison chemicals. All! There are no other statements possible that are absolutely true. How does all this relate to pre-emergence chemical concerns? Dumb question. 90% or more of those chemicals are non biodegradable.

I've seen Damask Perpetuals ("Portlands") with that look, especially when they grow in soil particularly to their liking. My 'Pickering Four-Seasons' and original 'Rose du Roi' look very much like the rose in these pictures when they're first coming out in the spring; and the 'Portland Rose' itself isn't too far off in its characteristics...