Plants › knotweed family
halberd-leaved tearthumb
Persicaria arifolia
28 photos
Study shows up to four per card, from different observers, so you learn the species rather than one picture. Heart the good ones and swap any you do not like.
Photos you add are credited to you, and you keep the copyright.
Easily confused with
arrow-leaved tearthumbPersicaria sagittata
hedge bindweedCalystegia sepium
mile-a-minute weedPersicaria perfoliata
sweet potatoIpomoea batatas
broadleaf arrowheadSagittaria latifolia
common dandelionTaraxacum officinale
prickly cucumberEchinocystis lobata
Carolina horsenettleSolanum carolinense
Study checks a spoken answer against these, and tells you which one you named.
Where it is recorded
| United States | 6,262 |
|---|---|
| New York | 1,102 |
| Virginia | 900 |
| Canada | 721 |
| Maryland | 666 |
| Massachusetts | 622 |
| New Jersey | 441 |
| Pennsylvania | 431 |
| Ontario | 429 |
| Connecticut | 252 |
Counts show where people looked, not only where it lives.
Classification
| Kingdom | Plants · Plantae |
|---|---|
| Phylum | Vascular Plants · Tracheophyta |
| Class | Dicots · Magnoliopsida |
| Order | pinks, cactuses, and allies · Caryophyllales |
| Family | knotweed family · Polygonaceae |
| Genus | knotweeds, smartweeds, and waterpeppers · Persicaria |
Study it in a deck
Or build your own from the species near you.
Sources
- Names, taxonomy and observation counts: www.inaturalist.org
- Photos and recordings: the creator and source are on each one.
- How much to rely on each source
Remember the name next time.
Practise halberd-leaved tearthumb with real photos from different observers. Say the name out loud, and it comes back just before you would forget it.