Eclipta L.
Eclipta is a small genus native to warm-temperate and tropical South America and Australia. Depending on species delimitation it counts one variable or up to six species (see Orchard & Cross 2013). One species, Eclipta prostrata, is a reputed agricultural weed, especially in rice-fields and other irrigated crops.
Literature:
Orchard A.E. & Cross E.W. (2013) A revision of the Australian species of Eclipta (Asteraceae: Ecliptinae) with discussion of extra-Australian taxa. Nuytsia 23: 43-62 [available online at: https://florabase.dpaw.wa.gov.au/science/nuytsia/648.pdf]
Unemoto S. & Koyama H. (2007) A new species of Eclipta (Compositae : Heliantheae) and its allies in eastern Asia. Thai Forest Bull., Bot. 35: 108-118. [available online at: https://www.tci-thaijo.org/index.php/ThaiForestBulletin/article/view/24209]
Urbatsch L.E., Baldwin B.G. & Donoghue M.J. (2000) Phylogeny of the Coneflowers and Relatives (Heliantheae: Asteraceae) Based on Nuclear rDNA Internal Transcribed Spacer (ITS) Sequences and Chlorplast DNA Restriction Site Data. Syst. Bot. 25(3): 539-565. [available online at: http://donoghuelab.yale.edu/sites/alienplantsbelgium.bedefault/files/099_urbatsch_systbot00.pdf]