Coprosma robusta, commonly known as karamū, is a flowering plant in the family Rubiaceae that is endemic to New Zealand. It can survive in many climates, but is most commonly found in coastal areas, lowland forests, or shrublands. Karamū can grow to be around tall, and grow leaves up to long. Karamū is used for a variety of purposes in human culture. The fruit that karamū produces can be eaten, and the shoots of karamū are sometimes used for medical purposes.
Description
thumb|left|1842 botanical illustration by [[Martha King of karamū in fruit]]
thumb|Karamū leaves and berries
Karamū is a large bushy shrub that grows up to tall. Branches are stout with no hair. Karamū stipules are black, hairless and obtuse with slightly serrated margin that are united at the base
Leaves
The glossy leaves of karamū range from long, with elliptic-oblong shape and acute or obtuse leaf apex and with obvious veins. The best flowering period is between August and September.
Etymology
The species epithet robusta means strong or sturdy. The Māori language name karamū has unclear etymological origins, but may be linked to the word kakara (scent).
New Zealand range
It is widely distributed across New Zealand in both the North and South Islands. On the Chatham Islands between Waitangi and Owenga, there is a small area where karamū has become naturalised.
Habitat preferences
Karamū 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.
The seed is largely dispersed by birds which eat the fruit. Due to its hardy characteristics, it is easy growing from seed even on open sites.
Again, as mentioned before, the best season for C. robusta fruiting is between April and May. It would finally grow up to six meters high and will normally act as a secondary succession plant during this process. It grows best in a moist soil They can also be found in coastal conditions, lowland scrub, swamps and rock associations.
Karamū is noted for its quick bushy growth and for this reason is commonly cultivated and frequently used for native bush regeneration projects.
Interactions
thumb|A [[tūī (Prosthemadera novaeseelandiae) feeding on karamū berries in Titirangi, Auckland]]
Birds which disperse karamū seeds include native bellbirds (Anthornis melanura) and tūī (Prosthemadera novaeseelandiae), indigenous silvereyes (Zosterops lateralis), and introduced blackbirds (Turdus merula), and song thrushes (Turdus philomelos). Seeds can be dispersed a long way and into areas of more mature forest.
Parasites
Karamū will sometimes act as a host plant to support other plants including podocarp, totara and yellow-wood family.
Food
The mature berries of karamū are a traditional Māori food,