streams that permeate the entire visual field. Flora New Caledonia's vegetation is distinguished by the world's highest rate of endemism: 5 families, 107 genera and 3,380 species. Among these are Acacia spirorbis, Dracophyllum species, Drosera neocaledonica, Grevillea gillivrayi, Neocallitropsis pancheri (Cupressaceae), and Austrotaxus spicatus (Taxaceae). Of the 44 species of Gymnosperm in the archipelago, 43 are endemic, including the unique parasite gymnosperm Parasitaxus ustus. The palm trees (Arecaceae) include 37 endemic species belonging to 16 genera. All Arecaceae species in the genera Actinokentia, Basselinia, Burretiokentia, Chambeyronia, Clinosperma, Cyphokentia, Cyphophoenix, Kentiopsis, and Pritchardiopsis are endemic to New Caledonia. For the endangered Pritchardiopsis jennencyi, one only adult specimen is known. Three of the most primitive genera of Araliaceae also occur. Some New Caledonia plant communities are true living fossils. Flora contains many groups of plants that appear to be remnants of the Gondwanan flora in late Cretaceous - early Tertiary that once covered large parts of Australasia. The flora is exceedingly diverse and includes a level of endemism, per square kilometre, seen almost nowhere else on Earth. Three-quarters of native plant species on New Caledonia are endemic, but a quarter of those are "at risk" of decline or extinction. There are besides 454 species of marine macrophytes. In contrast, several groups that are well represented in the rest of tropics have only a few species on the Archipelago, such as Melastomataceae with one species, or are absent all together, e.g., Ochnaceae (sensu stricto) and Begoniaceae. Other families, such as Araceae, Boraginaceae, Brassicaceae, Commelinaceae, Gesneriaceae, and Zingiberaceae, are substantially under-represented. Five families are considered endemic: the Amborellaceae, the Oncothecaceae, the Phellinaceae that was often included in Aquifoliaceae, the Paracryphiaceae, and the Strasburgeriaceae, before placed in Ochnaceae. Some genera originated in the Gondwanian Antarctic flora. The most remarkable Gondwanian groups include the Cunoniaceae, the Myrtaceae, the Escalloniaceae and the Proteaceae. Due to this fact, the islands share many plant families with the Valdivian forest of South America, New Zealand, Tasmania and Australia, in habitats of cloud forest and temperate rainforest. Angiosperm flora colonized New Zealand and New Caledonia during the Cretaceous with genera such as Nothofagus, Forgesia, and Polyosma. Many other groups reached New Caledonia after it separated from Australia, which took place as part of a widespread movement of Indo-Malesian elements that expanded into Australasia during the early and middle Tertiary. Some of these newer flora speciated intensively and are now among the