T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network

Melilotus indicus (Annual Yellow sweetclover)

Kingdom: Plantae
(unranked): Angiosperms
(unranked): Eudicots
(unranked): Rosids
Order: Fabales
Family: Fabaceae
Genus: Melilotus
Species: M. indicus
Binomial name: Melilotus indicus
Synonym: Trifolium indicum
Common names: Annual yellow sweet clover, Sweet clover , Sweet-clover), Sour clover, Indian sweet-clover, Annual yellow sweet clover, Bokhara clover, Small-flowered sweet clover, Common melilot, Small-flowered melilot, Small melilot, Sweet melilot, Californian lucerne and Hexham scent, King Island melilot or King Island clover.

Annual yellow sweet clover (Melilotus indicus) is a yellow-flowered legume native to northern Africa, Europe and Asia, but now naturalized throughout the rest of the world including New Zealand.
It is an annual or biennial herb from 10 to 50 centimetres in height (rarely up to one metre), with yellow, pea-like flowers that on ageing turn white. The flowers are 2 - 3 mm long and form in clusters along the flower stalks. The flowers produce a hairless, 1 to 2 seed pod of similar length.
The stalked leaflets (> 25 mm long) are trifoliate, aromatic, obtuse, denticulate margin and a blunt tip.

In New Zealand, it is found on roadsides, along railway tracks, coastal areas and on dry waste areas. It is a common weed in all the North Island except Taranaki. In the South Island, it is found in the north from Nelson down the south-east side to Bluff. It is also present on Stewart and Chatham Islands. 
It is poisonous to some mammals and is a potential seed crop contaminant.

Thanks to Wikipedia for text and information: