Polygonum cespitosum Blume var. longisetum (Bruijn) A.N. Steward
Longbristle Smartweed, Bristly Lady’s-thumb, Tufted Knotweed, Oriental lady's thumb
Persicaria longiseta; formerly Polygo num cespitosum var. longisetum — 2016/17 Winter native plant news (NC)

Synonyms
PECAL Persicaria caespitosa (Blume) Nakai var. longiseta (Bruijn) C.F. Reed, orth. var.
PELO10 Persicaria longiseta (Bruijn) Kitag.
POCAL2 Polygonum caespitosum Blume var. longisetum (Bruijn) A.N. Steward, orth. var. Oriental lady's thumb
POLO12 Polygonum longisetum Bruijn

Symbol: POCEL
Group: Dicot
Family: Polygonaceae
Duration: Annual
Growth Habit: Forb/herb
Native Status: CAN I, L48 I

"The cilia on the ocreae* are unmistakable: 1/4" to 3/8" long, per Wildflowers of the Southern Mountains." species
Evidently, this species may evolve the sort of "general-purpose genotypes" hypothesized by Herbert Baker to characterize an "ideal weed."

* a cup-shaped sheath formed by appendages at the base of a leaf, as in rhubarb, see the species comparison page


Longbristle Smartweed/Bristly Lady’s-thumb (Persicaria longiseta; formerly Polygo-num cespitosum var. longisetum) are amongcommon invaders. Longbristle Smartweed, anAsian native, is easily confused with Lady’s-thumb/Heart’s-ease (Persicaria maculosa, for-merly Polygonum persicaria), but this Eurasianspecies has very short bristles (up to 2 mmlong) extending from the sheath that sur-rounds the leaf node, while Longbristle Smart-weed has bristles that may be as long as 6mm). A native look-alike, Pennsylvania Smart-weed (Persicaria pensylvanica, formerly Po-lygonum pensylvanicum) lacks the bristles onthe leaf sheaths.
— 2016/17 Winter native plant news (NC) By Lisa Lofland Gould