What's that scarlet flower that brightens up the roadside banks of the lower Auckland Domain in late winter/early spring?
It is chasmanthe, a South African iris. Endemic to the Western Cape Province, chasmanthe (Chasmanthe bicolor) has naturalised sparingly in the Auckland region and near Whanganui.
The first wild collection in New Zealand was recorded in 1971 but the plants along the Lower Domain Drive have been spreading along the banks before then.
The tubular flowers are scarlet above and yellow and green underneath, with a long upper lobe. Silvereyes rob the nectar by piercing the flower at its base – and in so-doing fail to pollinate the flowers. The orange seeds in globular capsules are unusual – most irises have brown seeds.
In the same place there is also a clump of yellow-flowering chasmanthe. These flowers are larger and belong to a different species: C. floribunda.
The Auckland Museum herbarium holds 16 local collections of Chasmanthe bicolor. The earliest one is from the Auckland Domain in 1980.
Auckland Museum has more than 330,000 herbarium specimens in the collection; 250,000 herbarium records can be viewed online.
The text for this collection highlight was provided by Ewen Cameron - Curator of Botany at Auckland Museum.