Kingdom:   Plantae
(Unranked):        Angiosperms
(Unranked):        Eudicots
(Unranked):        Rosids
Order:       Fabales
Family:      Fabaceae
Subfamily: Faboideae
Tribe:        Galegeae
Subtribe:    Astragalinae
Genus:      Carmichaelia
Species:  C. astonii
Binominal name:  Carmichaelia astonii
Common name:  Astons Dwarf Broom, Dwarf NZ Broom.

Carmichaelia astonii is a rare dwarf spreading endemic broom of New Zealand and is found only in the South Island in Eastern Marlborough in a small area south of Ward, encompassing the Flaxbourne, Mead, and Waima (Ure) River catchments, Weld Cone, Ward Beach and the Chalk Range.
C. astonii is restricted to limestone areas in sparsely vegetated rendzina (a soil usually formed by weathering of soft rock types) and related steep land soils of medium to high fertility. This broom will tolerate -5°c to -12°c temperatures.

For more details visit: http://www.nzpcn.org.nz/flora_details.aspx?ID=408

Photographed at Otari Wilton Bush Reserve. November.
Carmichaelia astoni Dwarf New Zealand Broom -002.JPG

Carmichaelia astoni Dwarf New Zealand Broom -001.JPG

Carmichaelia astoni Dwarf New Zealand Broom -003.JPG

Photos below were below taken March.
Carmichaelia astonii Astons Dwarf Broom-001.JPG

Carmichaelia astonii Astons Dwarf Broom-002.JPG

Thanks to Wikipedia for text and information:

https://creativecommons.org/licenses/by-sa/3.0/