Thursday, January 17, 2013

Papua New Guinea 4. North Coast to the Sepik River

The Sepik River is New Guinea's Amazon, and a popular tourist destination.  The broad ribbon of water winds through vast lowland rain forests and sago swamps.  I was privileged to be part of two expeditions to this northwestern section of Papua New Guinea, and as a palm botanist, was ecstatic to find a great variety of palms, many previously unseen and unnamed by western botanists.  The first trip was in 1971, as part of the field work for my graduate study of New Guinea palms.  The second was in 1978, which I'll reserve for my next post.
The Sepik River winds its way for
700 miles through
northwestern Papua New Guinea.

Our first stop was at Vanimo, near the border with the Indonesian half of the island, called Irian Jaya.  The island of New Guinea was divided into three parts by colonial European powers.  The western half was occupied by the Dutch, and it eventually became part of Indonesia.  The northeast was occupied by Germany, who lost it to the Australians after the World War I.  The southeast, known as Papua, was colonized by the British and later administered by the Australians.  The two eastern sections were united into the independent nation of Papua New Guinea in 1975.

The highlight of the Vanimo area was an extensive natural population of Pigafetta, a relative of sago palms and vining rattans, a group characterized by scaly fruits.  Our wanderings also led us to Wutung Village and the border with Indonesia.  
The trunks of Pigafetta filaris are remarkably
The large inflorescence of Pigafetta contains hundreds of
flowers developing into scaly fruits.

A native of Wutung shows off his hand-made
hunting bow.

Your botany professor, impossibly young and
thin, at the marker of the border between
Papua New Guinea and Indonesia.

Turnera subulata, a native of central America, is cultivated
in Wutung.
Wild bird's nest fern (genus Asplenium) grows wild in
forests throughout New Guinea.
As we flew into the Sepik River basin in our tiny single-prop plane we could see vast populations of the sago palm, Metroxylon sagu.  We stopped at several places of somewhat higher ground to collect plants. We encountered many new palms, including a giant Orania near the village of Amanab.  I later named the species, Orania glauca.  The specific name refers to the waxy, or glaucous, covering of the inflorescence branches.
From the air we see that much of the Sepik Basin is occupied by vast stands of sago palm, Metroxylon sagu, which prefers swampy conditions.  The whitish-brown structures are the massive terminal inflorescences of the palms.  Each trunk blooms once, then dies.  As a build-up to the flowering phase, large quantities of starch are stored in the trunk.  This starch is harvested by the local people, and serves as their staple food.  

Orania glauca in forest near the village of Amanab.
Our local guide is dwarfed by the
inflorescence of Orania glauca.  Note
the whitish cast resulting from the waxy

The fruits of Orania are unusual among palms, in that up to
three one-seeded sections may form from a single flower.
Hydriastele valida was another new
species that we found.  This specimen
is growing near the village of Lumi.

This Rhopaloblaste species is similar to R. ceramica, otherwise known from the island of Ceram in Indonesia,
and differs from other New Guinea species by the pendulous (loosely hanging) leaflets of the fronds.
The bright red fruits of
 Rhopaloblaste cf. ceramica.

The branches of the Rhopaloblaste inflorescence
are tightly packed in bud, resembling a brain.
A lone specimen of an unidentified Livistona
near Lumi.