OF THE CAROLINAS & GEORGIA

Spermatophytes (seed plants): Angiosperms (flowering plants): Eudicots: Core Eudicots: Asterids: Campanulids: Asterales

WEAKLEY'S FLORA OF THE SOUTHEASTERN US (4/24/22):
Erigeron sumatrensis   FAMILY Asteraceae   Go to FSUS key



(?) PLANTS NATIONAL DATABASE:
Conyza floribunda   FAMILY Asteraceae

INCLUDED WITHIN Floristic Synthesis of North America. BONAP (Kartesz, 2015)

Erigeron sumatrensis

SYNONYMOUS WITH Floristic synthesis of North America. BONAP (Kartesz, 2010)

Conyza floribunda

SYNONYMOUS WITH Flora of North America north of Mexico, vol. 19-20-21 (2006)

Conyza floribunda

(?) Homotypic synonym

Conyza sumatrensis

 

COMMON NAME:
Tropical Horseweed, Sumatran Fleabane, Guernsey Fleabane


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

image of Erigeron sumatrensis, Tropical Horseweed, Sumatran Fleabane, Guernsey Fleabane

JK Marlow    jkm220906_9689

September    Greenville County    SC

Bald Rock Heritage Preserve

The tall columnar habit (characteristically 4-6' tall) of E sumatrensis makes it conspicuous, per Notes on the occurrence of Erigeron sumatrensis (Asteraceae) in Georgia (Nesom, 2018).

image of Erigeron sumatrensis, Tropical Horseweed, Sumatran Fleabane, Guernsey Fleabane

JK Marlow    jkm220906_9691

September    Greenville County    SC

Bald Rock Heritage Preserve

Capitulescence [compound inflorescence, as in Asteraceae] usually paniculate-thyrsoid, per Erigeron floribundus and E. sumatrensis (Asteraceae) in the USA and Mexico (Nesom, 2018).

image of Erigeron sumatrensis, Tropical Horseweed, Sumatran Fleabane, Guernsey Fleabane

JK Marlow    jkm220906_9694

September    Greenville County    SC

Bald Rock Heritage Preserve

image of Erigeron sumatrensis, Tropical Horseweed, Sumatran Fleabane, Guernsey Fleabane

JK Marlow    jkm220909_9773

September    Greenville County    SC

Bald Rock Heritage Preserve

E. sumatrensis in September is mostly in fruit, while many E. canadensis are in full flower, per Notes on the occurrence of Erigeron sumatrensis (Asteraceae) in Georgia (Nesom, 2018).

image of Erigeron sumatrensis, Tropical Horseweed, Sumatran Fleabane, Guernsey Fleabane

JK Marlow    jkm220909_9780

September    Greenville County    SC

Bald Rock Heritage Preserve

image of Erigeron sumatrensis, Tropical Horseweed, Sumatran Fleabane, Guernsey Fleabane

JK Marlow    jkm220909_9786

September    Greenville County    SC

Bald Rock Heritage Preserve

image of Erigeron sumatrensis, Tropical Horseweed, Sumatran Fleabane, Guernsey Fleabane

JK Marlow    jkm220909_9789

September    Greenville County    SC

Bald Rock Heritage Preserve

image of Erigeron sumatrensis, Tropical Horseweed, Sumatran Fleabane, Guernsey Fleabane

JK Marlow    jkm220909_9794

September    Greenville County    SC

Bald Rock Heritage Preserve

Involucre densely pubescent, vs that of E. canadensis or pusillus glabrous or sparsely pubescent, per Weakley's Flora (2022).

image of Erigeron sumatrensis, Tropical Horseweed, Sumatran Fleabane, Guernsey Fleabane

JK Marlow    jkm220909_9797

September    Greenville County    SC

Bald Rock Heritage Preserve

image of Erigeron sumatrensis, Tropical Horseweed, Sumatran Fleabane, Guernsey Fleabane

JK Marlow    jkm220909_9798

September    Greenville County    SC

Bald Rock Heritage Preserve

Cauline leaves characteristically narrowly lanceolate-elliptic to lanceolate or oblanceolate, per Weakley's Flora (2022).

image of Erigeron sumatrensis, Tropical Horseweed, Sumatran Fleabane, Guernsey Fleabane

JK Marlow    jkm220910_9845

September    Greenville County    SC

Bald Rock Heritage Preserve

Conyza sumatrensis is an obnoxious weed, emerging as an invasive species globally, per Seed germination ecology of Conyza sumatrensis populations stemming from different habitats and implications for management (Yanyun et al., 2021).

image of Erigeron sumatrensis, Tropical Horseweed, Sumatran Fleabane, Guernsey Fleabane

JK Marlow    jkm220910_9848

September    Greenville County    SC

Bald Rock Heritage Preserve

image of Erigeron sumatrensis, Tropical Horseweed, Sumatran Fleabane, Guernsey Fleabane

JK Marlow    jkm220910_9850

September    Greenville County    SC

Bald Rock Heritage Preserve

image of Erigeron sumatrensis, Tropical Horseweed, Sumatran Fleabane, Guernsey Fleabane

JK Marlow    jkm220910_9853

September    Greenville County    SC

Bald Rock Heritage Preserve

Fruiting receptacles 1.5-2.5mm wide, weakly but distinctly alveolate ["honeycombed"], per Erigeron floribundus and E. sumatrensis (Asteraceae) in the USA and Mexico (Nesom, 2018).

image of Erigeron sumatrensis, Tropical Horseweed, Sumatran Fleabane, Guernsey Fleabane

Steve Marlow    snm_090922_0115

September    Greenville County    SC

Bald Rock Heritage Preserve

 

 

WEAKLEY'S FLORA OF THE SOUTHEASTERN US (4/24/22):
Erigeron sumatrensis   FAMILY Asteraceae

(?) PLANTS NATIONAL DATABASE:
Conyza floribunda   FAMILY Asteraceae

INCLUDED WITHIN Floristic Synthesis of North America. BONAP (Kartesz, 2015)
Erigeron sumatrensis

SYNONYMOUS WITH Floristic synthesis of North America. BONAP (Kartesz, 2010)
Conyza floribunda

SYNONYMOUS WITH Flora of North America north of Mexico, vol. 19-20-21
Conyza floribunda

(?) Homotypic synonym
Conyza sumatrensis

 

Find by SCIENTIFIC NAME:

4637

Forb
Annual

Habitat: Disturbed areas, per Weakley's Flora

Non-native: Paleotropics

Uncommon in GA, rare in SC

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

LEAVES:
Simple
Alternate (basal leaves usually absent or withered at flowering)
Margins usually entire but can be fairly toothed

FLOWER:
Spring/Summer/Fall
Disc: White to pale yellowish Rays: Absent? very tiny (less than 0.3mm)?
Inferior ovary
Disc flowers bisexual & fertile/ Ray flowers pistillate & fertile

FRUIT:
Spring/Summer/Fall?
Achene

 

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



 


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