Senecio crassiflorus, in , one of the native South American Senecio and an herbaceous dune dwelling perennial.

 Senecio crassiflorus is not an upright herb, the silvery to white woolly 20 cm to 50 cm tall plant tends to "lay down and rest" on the dunes and sandy coastal areas it inhabits.
Leaves: Shaped like spatula with roundish, long, narrow, linear bases to having a broad rounded apex and a tapering base. Mostly 4 cm to 8 cm long, to 2 cm wide. The edges are smooth or toothed towards apex and both surfaces woolly.
Flowers: Broadly bell shaped, woolly flower heads appear singly or a few together, 1 cm to in diameter.
Seeds and reproduction: Achenes to ; pappus long.

:Reports claim S. crassiflorus does not produce viable seeds and spreads itself asexually or via vegetative reproduction.

Community species: *Ipomoea pes-caprae
:*Hydrocotyle bonariensis
:*Juncus acutus
:*Panicum sabularum
:*Spartina cf. ciliata
:*Hydrocotyle umbellata

Colombian communities: In a remote sensing project for rapid ecological evaluation, S. crassiflorus was found in Colombia inhabiting two areas that were evaluated.

A flood prone coastal region:

• Acanthospermum australe
• Acicarpha tribuloides
• Ambrosia tenuifolia
• Androtrichium trigynum
• Azolla sp.
• Bacopa monnieri
• Baccharis articulata
• Cardionema ramosissima
• Centella asiatica
• Cephalanthus glabratus
• Chenopodium retusum
• Cuphea carthagenensis
• Cynodon dactylon
• Cyperus haspan
• Cyperus virens
• Enydra sessilis
• Erechtites hieracifolia
• Eryngium pandanifolium
• Hedyotis salzmanii
• Ischaemum minus
• Juncus microcephalus
• Nymphoides indica
• Panicum racemosum
• Paspalum nicorae
• Petunia litoralis
• Pluchea sagitalis
• Polygonum punctatum
• Pterocaulon sp.
• Ranunculus apiifolius
• Sesbania punicea
• Solanum platense
• Thelipteris interrupta
• Xyris jupicai
• Zizaniopsis bonariensis

A sandy area near to a forest:

• Acanthospermun australe
• Baccharis arenaria
• Cynodon dactylon
• Fragmites communis
• Hydrocotyle bonariensis
• Mikania micrantha
• Myrcianthes cisplatensis
• Oenothera sp.
• Passiflora caerulea
• Polygonum sp.
• Salyx hunboldtiana
• Sapium glandulosum
• Schoenoplectus californicus
• Sebastiania schottiana
• Sesbania punicea
• Theliptheris interrupta
• Tillandsia aeranthos

Distribution: ;Native
:Neotropic:
::Brazil: Brazil
::Southern South America: Argentina, Uruguay
Current
:Neotropic:
::Brazil: Brazil
::Southern South America: Argentina, Uruguay
:Australasia:
::Australia: New South Wales
::New Zealand North: Wellington