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

Carmichaelia williamsii (Giant flowered broom)

Kingdom: Plantae
(unranked): Angiosperms
(unranked): Eudicots
(unranked): Rosids
Order: Fabales
Family: Fabaceae
Subfamily: Faboideae
Tribe: Galegeae
Subtribe: Astragalinae
Genus: Carmichaelia
Species: C. williamsii
Binomial name: Carmichaelia williamsii
Common name: Giant-flowered broom, Large Flowered Broom, William's Broom.

Carmichaelia williamsii is a strictly coastal species of broom growing >2 m. It is endemic to the North Island where it known mainly from the Poor Knights and Alderman Islands. On the mainland it is now known from only two small coastal areas near East Cape. Though it is rare in the wild it is sold by specialised nurseries. It habit is open forest, scrub, cliff faces.
This robust coastal shrub has erect leafless wide flattened yellow-green, green to dark green branches (>15mm wide) with wavy edges. These branches are are photosynthetic and serve as leaves. These wide branches distinguished it from the common introduced broom (Cytisus scoparius).
Flowering occurs usually from July and October. The flowers are pea-like and vary slightly in colour from yellow to white and sometimes striped with with purple or red veins. The seed pod is a dry flattened pod containing 5-15 hard orange and black seeds. These seeds are possibly dispersed by wind and granivory.

For more details visit: http://www.nzpcn.org.nz/flora_details.aspx?ID=58 

Photographed November at Christchchurch Botanical Gardens.


The top petal is called a standard, vexellum or banner an encloses and protects the other petals as the flower develops. The two lateral winged petals called alae. The two lower petals are fused along the purple line and are called a keel or carina. This is fusion is common in many members of the pea family.