Some may recall my request for ID of two plants that sprang up in our
garden in September/October -- I recorded them at
https://photos.app.goo.gl/5Ebgj4oWNHEwXkdi9

Plant "A" is the first two photos on that page, Plant "B" is the second
two photos.

(I think that) the consensus was that they are merely niger/nyger plants
that had sprung from discarded seed, thanks to the bizarre weather
conditions (so what's, now, new?) of this past year.

We've now had severe frosts, and it's bye-bye to the two mystery guests.
I took more photos before digging them up. These are at

https://photos.app.goo.gl/yhLaxss2tJX2QNGA6

(Don't forget to avail yourself of Googlephotos' magnifying glass if you
want a closer look.)

The first three are Plant "A", and the other 4 are plant "B".
You can see that A was still showing no signs of flowering, and also
that it has a conventional root system. (The hairy stalk, by the way,
was _not_ sticky, that I could detect.)

B was showing signs of flowering all over by this time, but of course
there was no chance of the flowers emerging. There was no tuber: just
conventional roots, again; an interesting stalk, I thought, hence the
cross-section photo.

Hope this is of interest to some!

Cheers
John