In my garden the first volunteer annual after (during) winter, is typicallySisymbrium irio, commonly known here as London Rocket. Apparently this disturbed land pioneer sprung up in the ash and rubble after the 1666 Great Fire of London, hence the name. It's origins are probably in the Middle East and North Africa where it is a traditional medicine for coughs and chest ailments.
Here in the northern Chihuahuan desert, this leafy little herb can be so enthusiastic about covering bare earth as quickly as possible, in cooler times after a moisture event (snow, rain if ever that happens) that it's presence on properties can, in my experience, earn one a weed citation from local municipal law enformance dept
Though it doesn't grow in neat rows, or come in a package from a grocery store or spring from a pretty seed packet, this is a valuable food plant offering itself especially abundantly at times when little else fresh and green is available. All parts of the plant are edible with a spicy pungency like the arugula or mustard greens family to which it belongs.
From personal observation, bees love the flowers coming at a time when, as for humans, there's not much else for them around. The deep taproot penetrates packed soil, improving soil health. Older plants , roots and all, make great biomass for the compost heap.
Ayurveda, one of the worlds oldest medical systems, would class this taste as pungent (katu) and in simple terms, since Ayurveda is really complicated, the pungent taste balances the kapha dosha, is heating, supporting digestive fire (agni), stomach, heart and circulatory systems.
A basic knowledge of plants would indicate to me that fresh picked leafy greens contain valuable nutrients for humans: off the top of my head maybe chlorophyll, vitamins, minerals and fiber.
Recently I have been enjoying a vegan pancake using this plant, finely chopped onion, thinly sliced pickled garlic or garlic chives or spring onions, grated carrot and any other suitable vegetable I might have on hand but mostly just those. Equal parts whole-wheat flour and chickpea flour (for protein and because I like the taste), a dash of olive oil and liquid (milk, plant based or dairy, or water you choose) 1-1 to the flours added to the vegetables makes the batter (seasonings like salt and black pepper optional, to taste)
Cooked in a cast iron skillet these are crispy, savory, delicious as is, or can be dressed up with chutney, another tasty medicine food with its origins in Indian Ayurvedic philosophy. A spicy dipping sauce could work too. They are a bit like Indian battered vegetable pakoras but don't require deep fat frying. I don't do deep hot oil in my kitchen. I saw enough burn scars on hands and arms of women and girls in India to make me very very leery of hot oil.
Though I'm mostly not big on accumulating random kitchen gadgets, a garlic slicer, originally purchased to slice garlic finely for dehydrating, is currently one of my much loved kitchen tools. It works just fine on pickled garlic yielding a pile of beautiful slices, perfect for putting in pancakes.
I found inspiration for these vegetable pancakes in Yachae Jeon, a traditional Korean side dish, and the late great chef and traveler Anthony Bourdain, who famously excoriated vegetarians, and would probably have taken his loaded with stinky seafood or nasty bits like chicken anuses.
"...What you are eating is always the end of a very long story..." Indeed.
If you are going to harvest volunteer plants for food or medicine, location matters. Roadsides in the USA can be sprayed with pesticides or the plants could be regularly bathed in exhaust fumes leaving a toxic coating that might outweigh the nutritional benefits.
And as always, as Frank Zappa taught us: watch out where the huskies go and don't you eat that yellow snow. In other words: have dogs peed on your food today?