The 'umbrella plant' in New Guinea

More than just a house plant

These are fascinating plants and are often small trees or shrubs but they may also grow on other trees (an epiphyte), sometimes quite high up.

They are found in many habitats: montane and lowland forest, swamp forest, scrub, and thickets in undisturbed and disturbed areas.

Schefflera pagiophylla, for example, grows in sub-alpine shrubberies and grassland up to 3,800m above sea level and S. gjellerupii, known only from a small area of the northern coast of New Guinea, was found growing on rocks on the shoreline. 

It's likely that Schefflera species are pollinated by insects and that birds mainly help to disperse the fruits and seed. 

Birds of Paradise are attracted to the nectar-producing flowers and in S. thaumasiantha the very large inflorescence can weigh up to 20kg. 

The fruits may be dispersed by parrots and possibly also by the Raggiana bird-of-paradise (Paradisaea raggiana).
 

The local people of the Ok Tedi area look out for S. eriocephala and S. setulosa when hunting for birds, as they know that birds are frequent visitors to the plants.

Some Schefflera species are used locally for medicinal purposes, or for their timber. Some have unusual uses, for example, the bark of S. forbesii is noted to be used in traditional wig decoration as a magic-adjunct.

Assessing the Umbrella plant

Using David’s data and analysis and other resources and research, we've managed to make extinction risk assessments for 69 different species of Schefflera in New Guinea.

Provisionally we have found that about one third can be classified as Least Concern (not currently considered at risk of extinction), one third as Data Deficient (insufficient information to assign a category) and one third as Threatened or Near Threatened.

Those that are Data Deficient could also be under threat, we just don’t know. Some haven’t been seen for more than 100 years, such as S. polychaeta, which is only known from one collection (the type specimen) made near Alkmaar, Papua Province, in 1907.

Those that are assessed as threatened often have very small ranges and are subject to ongoing or future threats, for example from logging, mining, conversion of habitat for agriculture or fires.

In New Guinea, climate change has led to an increase in the frequency and severity of drought, which makes the vegetation more at risk of fire and significant areas of montane forest have been burnt.

New Guinea still has much undisturbed forest and there are some conservation measures in place, although threats are increasing.

Our study of these plants highlights the fact that now is the time to make people aware of these threats. Such knowledge can inform conservation action to ensure that they continue to thrive in New Guinea’s rich and unique forest habitats.