Hello all!
I wanted to share some photos of a Czech variety of Lactuca serriola that I am cultivating. I hope that these pictures will help you to better identify Lactuca serriola in your own back yard.
Lactuca serriola is one of the more common of the useful varieties of wild lettuce. Serriola is perfectly fine for making tinctures and extracts. It has a good profile of sesquiterpene lactones, which are the naturally occurring analgesic compounds that give wild lettuces their sought after qualities.
Not all wild lettuces are useful for making tinctures. L. virosa is by far the best, but not commonly found. L. canadensis is not useful at all, but if you find it growing, chances are that serriola is not far off. If you find a canadensis growing in your yard, skip it and keep looking for the serriola.
Serriola is often referred to as prickly lettuce, though many wild lettuces have these spines. In fact there are varieties of serriola that do not have spines, but they are rare. There is also a variety of serriola called L. serriola integrifolia which does not have serrated leaves.
In most cases, serriola's leaves are rough and veiny. Serriola leaves are rigid, unlike the softer leaves of other lettuce varieties.
These pictures come from my seed crop garden in South Carolina, and were taken in June of 2022.

Notice the spines along the mid-rib.

Notice the rough and serrated shape of the leaves.

Spiny serriola leaves are quite tough and rigid, as is the whole plant. The stalk is very fibrous and will not break easily, unlike the typically hollow stalks of L. canadensis.

Serriola can grow very tightly together, where virosa's prefer some space.

Serriola stalks are usually thinner and more sparse than virosa stalks.

Serriola flowers are smaller than virosa flowers. To me they appear more dainty than other wild lettuce flowers.

Serriola has small yellow flowers which open in the morning.

When in the later stages of flowering and seeding, flowers are quite sparse and spread out. Serriola is a prolific seeder and spreads like wildfire.

Serriola seeds are smaller than virosa seeds, as well they are brown where virosa seeds are black. The unopen flower appears purple tipped. This is the same purple that often adorns the stalk.
Lactuca serriola can be found all over the United States, and indeed the world. According to the studies, serriola looks to be the progenitor of all lettuces, including garden lettuce.

I currently do not sell wild lettuce seeds, but if you want to grow or collect L. serriola, you can often find it in what used to be called "waste places". This could be something like the side of the road, a quarry, the unkempt outskirts of a train station or park, etc...
The best time to collect seeds is around 3pm when summer heat is in full swing.
Happy serriola hunting!
~ Christian Lactucaman

The original Czech serriola! This picture was snapped many moons ago when I first began collecting wild lettuce in the Czech republic.