Spermatophytes (seed plants): Angiosperms (flowering plants): Monocots: Asparagales
WEAKLEY'S FLORA OF THE SOUTHEASTERN US (4/24/22):
Iris pseudacorus
FAMILY
Iridaceae
Go to FSUS key
Dig deeper at SERNEC, a consortium of southeastern herbaria.
Check out EDDMapS.org to see where this has been reported.
Learn more about Yellow Flag from the Vascular Plants of North Carolina.
SYNONYMOUS WITH
PLANTS NATIONAL DATABASE:
Iris pseudacorus
FAMILY
Iridaceae
SYNONYMOUS WITH Flora of North America north of Mexico, vol. 26 (2002)
Iris pseudacorus
SYNONYMOUS WITH VASCULAR FLORA OF THE CAROLINAS (Radford, Ahles, & Bell, 1968) 046-05-005:
Iris pseudacorus FAMILY Iridaceae
SYNONYMOUS WITH Manual of the Southeastern Flora (Small, 1933, 1938)
Iris pseudacorus
COMMON NAME:
Yellow Flag, Water Flag, Yellow Iris
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_irps_001_lvd
)
USDA-NRCS PLANTS Database / USDA Wetland flora: Field office illustrated guide pnd_irps_008_lvd
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Rob Hunnings rlh_10411C
May Greenville County SC
Lake Conestee Nature Park
The only completely yellow, large, wild iris in North america, per Invasive Plants, Guide to Identification, Impacts and Control (Kaufman & Kaufman, 2007).
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Rob Hunnings rlh_10415
May Greenville County SC
Lake Conestee Nature Park
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Rob Hunnings rlh_10417
May Greenville County SC
Lake Conestee Nature Park
)
Rob Hunnings rlh_10532C
May Greenville County SC
Lake Conestee Nature Park
Once established, can form dense clumps that exclude other wetland species, per Invasive Plants, Guide to Identification, Impacts and Control (Kaufman & Kaufman, 2007).
)
Rob Hunnings rlh_10537
May Greenville County SC
Lake Conestee Nature Park
The 3 drooping, deep yellow sepals are marked with purple-brown, per Invasive Plants, Guide to Identification, Impacts and Control (Kaufman & Kaufman, 2007).
)
Rob Hunnings rlh_10544
May Greenville County SC
Lake Conestee Nature Park
The 3 narrow petal-like sections are flattened branches of the style, per The Monthly Illustrator, Vol 4 (Jones, 1895).
)
Rob Hunnings rlh_10547
May Greenville County SC
Lake Conestee Nature Park
Sword-like flattened leaves (3/4" wide to 3' long) arise in a fan from base, per Invasive Plants, Guide to Identification, Impacts and Control (Kaufman & Kaufman, 2007).
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Patrick D. McMillan pdmipseudacorus_lvl
June Avery County NC
3 short erect petals, and 3 sepals with broad rounded down-curved tips, per Wildflowers of Tennessee, the Ohio Valley, and the Southern Appalachians (Horn, Cathcart, Hemmerly, & Duhl, 2005).
WEAKLEY'S FLORA OF THE SOUTHEASTERN US (4/24/22):
Iris pseudacorus
FAMILY
Iridaceae
SYNONYMOUS WITH
PLANTS NATIONAL DATABASE:
Iris pseudacorus
FAMILY
Iridaceae
SYNONYMOUS WITH
Flora of North America north of Mexico, vol. 26
Iris pseudacorus
SYNONYMOUS WITH
VASCULAR FLORA OF THE CAROLINAS (Radford, Ahles, & Bell, 1968) 046-05-005:
Iris pseudacorus
FAMILY
Iridaceae
SYNONYMOUS WITH
Manual of the Southeastern Flora (Small, 1933, 1938)
Iris pseudacorus
763
Forb
Perennial
Habitat: swamps, marshes, streams, ponds, streambanks, tidal wetlands, cultivated as a water plant, per Weakley's Flora
Non-native: Eurasia & Africa
Uncommon (rare in Coastal Plain of GA & SC)
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:
- Brooklyn Botanic Garden
- Kentucky Exotic Pest Plant Council, 2013
- Tennessee Exotic Pest Plant Council, 2009
- Virginia Department of Conservation and Recreation, 2014
LEAVES:
Simple
FLOWER:
Spring/Summer
Yellow/Cream
Radially symmetrical
3 sepals
3 petals
3 stamens
Inferior ovary
Bisexual
FRUIT:
Summer/Fall
Capsule
TO LEARN MORE about this plant, look it up in a good book!
- Invasive Plants, Guide to Identification, Impacts and Control (Kaufman & Kaufman, 2007) p241
- Newcomb's Wildflower Guide (Newcomb, 1977) p120
- Wildflowers of the Atlantic Southeast (Cotterman, Waitt, & Weakley, 2019) p273
- Field Guide to the Wildflowers of Georgia (Chafin, 2016) p384
- Wildflowers of Tennessee (Carman, 2005) p388
- Wildflowers of Tennessee, the Ohio Valley, and the Southern Appalachians (Horn, Cathcart, Hemmerly, & Duhl, 2005) p443
- Wildflowers of the Southern Mountains (Smith, 1998) p020
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".