Included here is the Bismarck Archipelago, the Admiralty Islands and the Solomon Islands. All lie within the Pacific zone of Melanesia.

On the Solomon Islands these forests reach heights of between 30 and 45 m, but the canopy is occasionally exceeded in height by a few emergent species such as the strangling and banyan figs (Ficus benjamina, F. glandulosa, F. obliqua, F. subcordata, F. virgata and F. xylosycia) and Terminalia calamasanai.  Altogether in these relatively species poor forests there are some 20 common canopy trees including Calophyllum kajewskii, Calophyllum vitiense, Campnosperma brevipetiolum, Elaeocarpus sphaericus, Endospermum medullosum, Gmelina molluccana, Maranthes corymbosa, Pometia pinnata, Schizomeria serrata, and the endemic Dillenia salomonensis (Dilleniaceae) and Parinari salomonensis (Chrysobalanaceae). Other less common endemic trees are Callophyllum confusum, C. obscurum (Hypericaceae), Elaeocarpus polyandrus (Elaeocarpaceae), Fagraea obtusifolia (Loganiaceae), Myristica kajewskii (Myristicaceae), Terminalia rerei and T. whitmorei (Combretaceae).  In lowland rain forest of the Bismarck Archipelago other endemic trees have been found including Chisocheton novobritannicus (Meliaceae) and Elaeocarpus neobritannicus (Elaeocarpaceae) on New Briton, and Elaeocarpus rubescens (Elaeocarpaceae), Helicia peekelii (Proteaceae) and Osmoxylon lanceolata (Araliaceae) on New Ireland, while Helicia neglecta and Osmoxylon pfeilii occur on both New Briton and New Ireland.

The undergrowth of Solomon’s lowland forests is characterized by an abundance of pachycaul treelets (thick stemmed trees with few branches). These possibly primitive life forms appear have now been swamped by the more competitive leptocaul trees (trees with abundant branches) in the jungles of central Malesia. Solomons’ pachycaul species include Barringtonia papeh, Leea indica, Piper wichmannii and Taperinosperma pachycauloum. Other lower story species include the small endemic tree Elaeocarpus coodei (Elaeocarpaceae), and endemic shrubs such as Geniostoma rupestre var. solomonense (Loganiaceae) and Osmoxylon confertiflorum (Araliaceae).  In contrast with other ecological groups within these forests, climbers and epiphytes are much more abundant than in the forests of West Malesia. Tree trunks are often completely obscured by bole climbers and epiphytes. Aroids are particularly abundant and include the endemic or near endemic Scindapsus salomonensis and Spathiphyllum solomonensis (Araceae). Higher up, various semi-parasitic aerial shrubs occur including the endemic Dactyliophora solomonia and Sogerianthe versicolor (of the Loranthaceae).

On the Solomons certain large tree species like Planchonella thyrsoides and the endemic Albizia salomonensis (Fabaceae) and Archidendron oblongum (Fabaceae) are confined to the rich alluvial valleys. This is also the main habitat of palms, with the principal species being Areca macrocalyx and the endemic Rhopaloblaste elegans (Arecaceae), and other giant monocotyledonous plants like Heliconia indica, the gingers Catimbium novae-pommeraniae, Costus speciosus and Guillainia purpurata and members of the Marantaceae such as Cominsia gigantea and Donax cannaeformis.

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