Ethulia conyzoides

This plant ranges from western, northern, central, and southern Africa, Eurasia (Syria) to tropical Asia and eastward from China to south America (Brazil). It has been widely introduced and the species natural range requires confirmation.
Native: Bangladesh; Benin; Botswana; Brazil; China; Côte d'Ivoire; Egypt; Ethiopia; Gambia; Ghana; Guinea; India; Indonesia; Kenya; Lao People's Democratic Republic; Madagascar; Malawi; Malaysia; Mozambique; Myanmar; Philippines; Senegal; Sierra Leone; Sri Lanka; Taiwan, Province of China; Thailand; Viet Nam; Zambia; Zimbabwe
It is an invasive, semi-aquatic weed commonly found growing on moist soils; fairly common in India. The species is typically occurs on moist soils, in shallow water or on marshy ground on river banks and in low-lying areas, as well as in reed beds often mixed with species such as Salvinia natans. It also occurs in rice fields where it may become a pest.
Its leaves are used as food. Its roots and whole plant are important medicinals for local people. Ecologically, the plant is good oxygenator of water.
Citation:Gupta, A.K. 2011. Ethulia conyzoides. The IUCN Red List of Threatened Species 2011: e.T164429A5864268. Downloaded on 11 April 2017.

ID of herb KD 05 April 2015 : 5 posts by 4 authors. Attachments (5)
Attached images are wetland herb. Please ID the herb.  
Date :12.04.2015
Location: Assam
Family : Apiaceae (??)
Genus & species :??
Habitat: Grows wild on ditches
Habit : Herb
... could it be some species of Pluchea (of Asteraceae) ?
Pluchea species in eFIoraofindia (with details/ keys from published papers/ regional floras/ FRLHT/ FOI/ efloras/ books etc., where ever available) 
Don't have any idea if it comes from Apiaceae or Asteraceae.
The above plant specimen(earlier identified as Pluchea) is identified as Ethulia conyzoides L.f (Asteraceae) which is matched with Kew Herbarium(K001118767). Here I attached images of my herbarium and kew  voucher specimen. Attachments (2)