Sophora: Kowhai Family: Papilionaceae (pea or Legume family)
There are 30 species.of Sophora found in temperate and subtropical regions of both Hemispheres. The
Sophora tetraptera is a tree up to 12 metres tall. Leaves can be up to 15 cm long with leaflets 3.5 X 8mm. The golden yellow flowers are up to 5 cm long. There is no divaricating juvenile form. Its distribution is on lowland stream sides and forest margins on the eastern side of both islands.
Sophora microphylla is a tree to about 10 metres tall. Leaves are up to 15 cm long, however what differentiates it from Sophora tetrapetera, is the small leaflets are never longer than 1 cm. The flowers are slightly smaller as well and are coloured pale to golden yellow. It may have a divaricating juvenile form. Its distribution is through all of
Sophora prostrata is a prostrate or bushy shrub up to 2 metres tall. Leaves may be up to 2.5 cm log, usually smaller. Leaflets are no larger than 4mm.
Kowhai is another of
The flower of the kowhai is the national flower of
Like all legumes Kowhai have bacterial nodules on their roots that transfer gaseous nitrogen into soil soluble nitrates, an excellent fertiliser. Note the similarity of the seed pod to the other legumes peas and beans.
The seed is adapted for dispersal by floating which accounts for its abundance on stream sides, where floods carry the seeds throughout the catchments system. Native birds such as pigeon feed on the seed pods using the tough seeds as gizzard stones to masticate their food. Pigeons have been observed eating the leaf as well.
The seeds of kowhai have a dormancy mechanism, that being, their tough seed coat (testa) that is impervious to water unless nicked with a sharp knife or scalpel. Soak overnight and sow in a warm, sunny spot. Germination should proceed within 20 days. A plant 30-40 cm high can be attained one year after germination.
It is said that the Kowhai sprung from the shreds of the cloak of tohunga Ngatoro-I-rangi of the Te Arawa waka on its arrival to Aotearoa. The legend says that a young tohunga asks a girl to marry him while they sit under the bare branches of a Kowhai tree in the month of August. She replies that she will only marry him if he can perform some brilliant act. “I will show you what I can do. I will cause this tree to spring instantly into flower before your eyes.” He uses all his powers and the tree bursts into bloom, his final touch causing a ring of yellow blossoms to appear around the dark hair of the girl. Ever since, say Te Arawa, the Kowhai has flowered on bare and leafless branches
There is a saying in the
P. Williams Te rongoa maori.
The Kowai is met with principally on the banks of rivers: In the season of spring this tree makes a beautiful appearance , being entirely covered with bright chrome or golden coloured flowers which hang corymbriated, and succeeded by long pendulated pods, the especial food of the Tui and other birds. Its beauty is not dimmed by the reflection in the adjacent stream.
kowhai make excellent plant studies for students of all ages.
I recommend the following books on New Zealand native plants