But actually the said volunteers decided the Jasmine needed to be sprayed, probably after being trimmed back a bit first, as there were too many rooted stems spreading the shrub around. The 100s of stems removed are all other things - wisteria, ivy, sweet briar, ash trees, nettle tree, privet, and possibly also Virginia creeper - I did not get a photo of that creeper.
@JaneR i search in the general search box for this species and then found this species here: Xyris gracilis already in the Lillies and Irises sub-category (within Plants category) .