NZ Coprosma Key

Identify New Zealand species of Coprosmas

This free app is an identification key to New Zealand species of Coprosma. New Zealand has about 60 species of Coprosma (the number is uncertain because of undescribed entities). There are between 5 and 13 species in New Guinea, 8 species in Australia, and c. 13 species in Hawai'i.

The nearest relatives of Coprosma are Nertera, a widespread genus that includes 8 New Zealand species; Leptostigma, a smaller genus that includes one New Zealand species, Leptostigma setulosa; Durringtonia, a genus of one Australian species; and Normandia, a genus of one New Caledonian species (Markey et al. 2004 conference abstract).

In New Zealand, Coprosma is distinguished from Nertera and Leptostigma by being woody. Those other two genera lack woody tissue. All three genera have opposite leaves and the distinctive interpetiolar stipule which is the feature that best distinguishes Coprosma species from other New Zealand shrubs that have opposite leaves.

DNA studies (Markey et al. 2004 conference abstract) indicate that the Western Nelson endemic Coprosma talbrockiei, does not belong in Coprosma and is most closely related to Australian Durringtonia. It is retained in this key as Coprosma because it has not yet been assigned to another genus. It is the only species in the key which has leaves in threes, not in pairs.

This key was designed to be used by someone who already has some skills in plant identification. It assumes that you are able to identify that you have a Coprosma rather than a plant of another genus. If you are unsure of the genus, we recommend Wilson & Galloway's (1993) Small-leaved shrubs of New Zealand, which includes all the genera that are similar to the small-leaved coprosmas. This key also assumes some knowledge of botanical terminology, we have used terms like glabrous, petiole, and stipule, and these are defined in the glossary. We have attempted to simplify the terminology whereever possible to make the key useable for as wide an audience as possible.

The key should be particularly useful to anyone who needs to be able to make correct identifications of Coprosma species using material that may not be ideal, in particular, using plants that lack ripe fruit. Ripe fruit are generally only available in autumn, while the season when most fieldwork is done in summer. This is one of the reasons for constructing this key, to get around the frequent lack of availability of fruit. The other reason for constructing this key is to include all of the new species published in the last 10 years (e.g. in Jane 2005).