Coprosma robusta

Naming

''Coprosma robusta'', known by the common name karamu, is a large bushy shrub that grows up to 6 meters tall. Branches are stout with no hair. Domatia and stipules are significant characteristic features of Coprosmas Karamu stipules are black, hairless and obtuse with slightly serrated margin that are united at the base

Habitat

Karamu can be widely found near coastal, lowland and lower montane areas. It can also grow within shrub lands and expansive areas within dense trees such as lowland forest. However, the population decreases in lowland forest such as beech and kahikatea forests. Normally karamu is a hardy plant that can adapt to infertile soils, poorly drained and exposed lands. It can also grow in a large range of altitude varying from 0–1200 meters under full sun to shady, windy and frosty circumstances.

Food

The mature berries of karamu can be eaten as food, and its leaves used to make a tea drink.

Predators

Herbivorous mammals such as goats and deer have a severe impact on karamu, and hares and rabbits eat the seedlings.. Additional consumers of karamu are ''Batracomorphus'', ''Batracomorphus adventitiosus'', leafhoppers and Membracoidea.

Defense

It is one of the first seven ''Coprosma'' species that were collected by Joseph Banks with Cook's voyage to New Zealand. At that time, ''Coprosma robusta'' was called ''Pelaphia lata''.

In recent years, there is a report showing the sex ratio of karamu in the Riccarton Bush in Christchurch. The sex ratio of population of is female-biased with 70% of the flowering plants being female. This female-biased ratio differs from the few other counts of sex ratios in New Zealand species of ''Coprosma''. That could be influenced by a number of factors, including the pollen and seed fecundity of the two sexes and factors affecting their sexual maturity and mortality. That is interesting because karamu is often male-biased in sex ratios. This differential survival of the sexes in long-lived species is usually attributed to differences in reproductive effort between male and female plants. In particular, the energy cost of producing ovules and fruit in female plants is greater than the cost of male flowers producing pollen. Female-biased sex ratios also occur as a consequence of differential fertilization and genetic differentiation of sex chromosomes.

Uses

Juvenile shoots can be applied to release inflammation or bladder problems if boiled and then the liquid drunk. The leaves are believed by Maori to have the ability to deal with kidney troubles and bark can be and used to treat stomachache and vomiting.