Welcome and unwelcome weeds

The summer harvest from the allotment is paying back the hard work early in the year. Even the many trips to the distant tap through the long dry spell seem worthwhile as the tasty produce is eaten up.

But among the vegetables, there is a thriving underworld..... of bugs, worms, and of course weeds. I am aware that many of my recent posts have dwelt on the need to get rid of introduced species to benefit the native ones in the wild, but on the allotment and (to a lesser extent) in the garden the reverse applies.
I'm very pleased to report, however, that six healthy plants of Round-leaved Fluellen have appeared unbidden on the plot. I thought the species was declining like many other arable weeds, but "Like Kickxia elatine [Sharp-leaved...], this species has a similar range to that mapped in the 1962 Atlas. Although both species are often thought to be declining, they have never been abundant weeds and the distribution may be more stable than is often supposed..... some Kickxia seeds germinate in late summer and may therefore escape herbicides."

A brief look on the net failed to find the derivation of the name, although the Welsh Llysiau Llywelyn translates as Llywelyn's vegetable, so it may be linked with one of the Welsh princes..... Llywelyn ap Gruffydd, or maybe Gruffydd ap Llywelyn.

This ancient British weed is joined on my patch by a relatively new one, Shaggy Soldier, which - with its relative Galant Soldier - is romping through the market gardens of England after an accidental introduction from Peru.
A plant can distribute about 7500 seeds a year, these can germinate almost immediately and the natural spread of the plant is 10 miles per year! This plant needs hoeing out without delay, or I'll be swamped.
Also on the plot is an imposing specimen of Great Lettuce, approaching six feet tall. Domestic lettuces are apparently derived from Prickly Lettuce Lactuca serriola, and fortunately the spines have been bred out over the centuries.
Not on the allotment but on a nearby field edge is this Dwarf Spurge, the only one I've found so far in the parish: