I found an article about Fiji longan varieties grown in my hometown from 1984 and here is an extract,
From the seedling stage the trees take 3 to 4 years to bear. Their frost tolerance is as yet unknown.
No clonal varieties have been named yet, although 5 different types of seedlings are now growing in the Cairns area. They are:
(1) The smaller brown-skinned type from Irian Jaya.
(2) The round green type from Fiji.
(3) The large, soft-skinned type from New Ireland.
(4) The purple and green hard-shelled type from New Britain.
(5) The hard-shelled green and red fruit from Wewak in Papua New Guinea.
The fruit is known under the names "Taun" Matoa, Fiji Longan, and Dawa.
People who know the fruit speak highly of it, although commercially, it is sold only in local markets in its native area. The tree is reported to grow well in soils with a high pH factor.
The tree is one of Papua New Guinea's most commercial timbers and is exported as "Taun". It reaches a height of 30 metres (100 ft) in the jungle, but when grown in the open (in backyards), it reaches about 15 metres and is similar in shape to a small mango tree.
John Marshall
DATE: May 1984
The New Ireland one sounds like a good match for the one originally pictured in this thread. Similar forms also seem to be present in PNG,New Britian and Fiji.