Polygonum ilanense Y.C.Liu & C.H.Ou 1976 https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:695895-1
NOT Persicaria foliosa (H.Lindb.) Kitag.
Reference observation:
https://www.inaturalist.org/observations/232920381
https://www.inaturalist.org/observations/226387444
https://www.inaturalist.org/observations/229773710
https://www.inaturalist.org/observations/91948643
Although commonly considered an ant-plant, water and cockroaches are the only recorded contents but more field work will probably add other infauna. I post this primarily to show that the much vaunted scaphoid (boat-shaped) tubers are not a consistent feature. Also to correct the misspelling on my previous example. This system frustrates all of my attempts to correct the missing letter i.