OF THE CAROLINAS & GEORGIA

Spermatophytes (seed plants): Angiosperms (flowering plants): Eudicots: Core Eudicots: Caryophyllales

WEAKLEY'S FLORA OF THE SOUTHEASTERN US (4/24/22):
Alternanthera philoxeroides   FAMILY Amaranthaceae   Go to FSUS key



SYNONYMOUS WITH PLANTS NATIONAL DATABASE:
Alternanthera philoxeroides   FAMILY Amaranthaceae

SYNONYMOUS WITH Floristic Synthesis of North America. BONAP (Kartesz, 2021)

Alternanthera philoxeroides

SYNONYMOUS WITH Flora of North America

Alternanthera philoxeroides

SYNONYMOUS WITH VASCULAR FLORA OF THE CAROLINAS (Radford, Ahles, & Bell, 1968) 066-01-002:

Alternanthera philoxeroides   FAMILY Amaranthaceae

SYNONYMOUS WITH Manual of the Southeastern Flora (Small, 1933, 1938)

Achyranthes philoxeroides

 

COMMON NAME:
Alligator-weed


         To see larger pictures, click or hover over the thumbnails.

image of Alternanthera philoxeroides, Alligator-weed

USDA-NRCS PLANTS Database / USDA Wetland flora: Field office illustrated guide    pnd_alph_003_lvd

        

image of Alternanthera philoxeroides, Alligator-weed

USDA / Selected Weeds of the US. 1970    swus_page_141

        

image of Alternanthera philoxeroides, Alligator-weed

Richard and Teresa Ware    rtw_a_philoxeroides

June        

Small, white, rounded cloverlike clusters of tiny flowers are 0.5-0.7" wide, per A Field Guide for the Identification of Invasive Plants in Southern Forests (Miller, Chambliss, & Lowenstein, 2010).


click here to see other plants that look similar to this COMPARE aquatic plants

image of Alternanthera philoxeroides, Alligator-weed

JK Marlow    jkm160914_110

September        

SE-EPPC Aquatic Plant ID Workshop

image of Alternanthera philoxeroides, Alligator-weed

James H. Miller, USDA Forest Service, Bugwood.org    bug_1539028

Month Unknown        

Leaves somewhat succulent, obtuse to rounded at the tip, per Weakley's Flora (2012).

image of Alternanthera philoxeroides, Alligator-weed

Gary Buckingham, USDA Agricultural Research Service, Bugwood.org    bug_4723003

Month Unknown        

Each flower w 5 minute petals (actually sepals) surrounding yellow anthers, per A Field Guide for the Identification of Invasive Plants in Southern Forests (Miller, Chambliss, & Lowenstein, 2010).

image of Alternanthera philoxeroides, Alligator-weed

Julia Scher, Federal Noxious Weeds Disseminules, USDA APHIS ITP, Bugwood.org    bug_5376307

Month Unknown        

image of Alternanthera philoxeroides, Alligator-weed

James H. Miller, USDA Forest Service, Bugwood.org    bug_5379494

Month Unknown        

image of Alternanthera philoxeroides, Alligator-weed

James H. Miller, USDA Forest Service, Bugwood.org    bug_5422002

Month Unknown        

image of Alternanthera philoxeroides, Alligator-weed

Nancy Loewenstein, Auburn University, Bugwood.org    bug_5471274

Month Unknown        

Bracts not keeled. Peduncles 1-7cm, from the leaf axils or terminal, per Weakley's Flora (2012).

 

 

WEAKLEY'S FLORA OF THE SOUTHEASTERN US (4/24/22):
Alternanthera philoxeroides   FAMILY Amaranthaceae

SYNONYMOUS WITH PLANTS NATIONAL DATABASE:
Alternanthera philoxeroides   FAMILY Amaranthaceae

SYNONYMOUS WITH Floristic Synthesis of North America. BONAP (Kartesz, 2021)
Alternanthera philoxeroides

SYNONYMOUS WITH Flora of North America
Alternanthera philoxeroides

SYNONYMOUS WITH VASCULAR FLORA OF THE CAROLINAS (Radford, Ahles, & Bell, 1968) 066-01-002:
Alternanthera philoxeroides   FAMILY Amaranthaceae

SYNONYMOUS WITH Manual of the Southeastern Flora (Small, 1933, 1938)
Achyranthes philoxeroides

 

Find by SCIENTIFIC NAME:

2937

Emergent aquatic (rooted along shoreline, but floating mats can detach); Forb
Perennial

Habitat: Floating in mats on the surface of the waters of blackwater rivers, sloughs, ditches, ponds, and in very moist soil of ditches and shores, per Weakley's Flora

Non-native: tropical America

Common in Coastal Plain, uncommon in Piedmont, rare in Mountains

map
CLICK HERE to see a map, notes, and images from Weakley's Flora of the Southeastern US.

Click here to see a map showing all occurrences known to SERNEC, a consortium of southeastern herbaria. (Zoom in to see more detail.)


INVASIVE

This plant is causing problems in natural areas outside its native range, according to authorities such as:

 

LEAVES:
Simple
Opposite

FLOWER:
Spring/Summer/Fall
White
5 sepals
Petals absent
5 stamens, united at base
Bisexual

FRUIT:
Spring/Summer/Fall
Utricle

 

TO LEARN MORE about this plant, look it up in a good book!



 


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