In this documentary the part of the sunflower is played by Helianthus annuus.
I am grateful for the assistance of my wife, Karen, and to the legion of plant suppliers whose prolific supply of seed catalogues forms an excellent and nourishing mulch in our flower beds.
Scientific note: John Gerard, master in chirurgerie, says in his 1597 book “The Herball, or, Generall historie of plantes” regarding “the flower of the Sunne”
[...] a plant of such stature and talenesse, that in one sommer being sowen of a seede in Aprill, it hath risen up to the height of fourteene foote in my garden, where one flower was in waight three pounde and two ounces, and crosse overthwart the flower by measure sixteene inches broade.
[...] those that have reported it to turne with the sunne, the which I coulde never observe, although I have endevored to finde out the truth of it