Spermatophytes (seed plants): Angiosperms (flowering plants): Eudicots: Core Eudicots: Rosids: Malvids: Myrtales
WEAKLEY'S FLORA OF THE SOUTHEASTERN US (4/24/22):
Trapa natans
FAMILY
Lythraceae
Go to FSUS key
Dig deeper at SERNEC, a consortium of southeastern herbaria.
Check out EDDMapS.org to see where this has been reported.
SYNONYMOUS WITH
PLANTS NATIONAL DATABASE:
Trapa natans
FAMILY
Trapaceae
SYNONYMOUS WITH Floristic Synthesis of North America. BONAP (Kartesz, 2021)
Trapa natans
INCLUDED WITHIN Flora of China
Trapa natans
SYNONYMOUS WITH Flora of North America
Trapa natans
COMMON NAME:
European Water-chestnut, Water-caltrop, Four-spined Water-chestnut
To see larger pictures, click or hover over the thumbnails.
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USDA-NRCS PLANTS Database / Britton, N.L., and A. Brown. 1913 pnd_trna_001_lvd
WEAKLEY'S FLORA OF THE SOUTHEASTERN US (4/24/22):
Trapa natans
FAMILY
Lythraceae
SYNONYMOUS WITH
PLANTS NATIONAL DATABASE:
Trapa natans
FAMILY
Trapaceae
SYNONYMOUS WITH
Floristic Synthesis of North America. BONAP (Kartesz, 2021)
Trapa natans
INCLUDED WITHIN
Flora of China
Trapa natans
SYNONYMOUS WITH
Flora of North America
Trapa natans
3797
Emergent aquatic (rooted); Forb
Perennial
Habitat: Farm ponds and other stagnant or slow-moving water, per Weakley's Flora
Non-native: Eurasia & Africa
CLICK HERE to see a map, notes, and images from Weakley's Flora of the Southeastern US.
This plant is causing problems in natural areas outside its native range, according to authorities such as:
- Forest Health Assessment & Applied Sciences Team: New Invaders of the Southeast
- SC Department of Natural Resources Aquatic Nuisance Species List, 2003
- SC List of Regulated Pest Plant Species, 2017
- Tennessee Exotic Pest Plant Council, 2009
- Virginia Department of Conservation and Recreation, 2014
IS THE PLANT "ARMED"?
Fruit armed with 2-4 prominent spines
LEAVES:
Submerged leaves finely divided, feather-like; floating leaves simple
Submerged leaves alternate; floating leaves in a rosette at water's surface
Petioles of floating leaves 2-6' long
FLOWER:
Summer/Fall
White (inconspicuous)
4 sepals
4 petals
Flowers borne in the center of the rosette of floating leaves
FRUIT:
Nut-like
TO LEARN MORE about this plant, look it up in a good book!
- Invasive Plants, Guide to Identification, Impacts and Control (Kaufman & Kaufman, 2007) p419
- New Invaders of the Southeast (Rawlins et al., 2018) p107
If a search such as "Carex leptalea var. leptalea" doesn't deliver the results you want, try "Carex leptalea".
Or, to minimize chances of a misspelling, try just "Carex le".
Less is more: If "pencil flower" doesn't deliver the results you want, try "pencil".