Flora is the collective term for all plant life found in a specific region or period of the Earth’s history, including vascular plants, mosses, ferns, green algae, and red algae. Funga is the corresponding term referring to fungi, including lichen-forming fungi (lichens).
The species composition of Iceland’s flora is closest to that of mainland Scandinavia. A lesser similarity can be seen with the flora of the British Isles (Scotland in particular) and Greenland. Local flora differs considerably within Iceland. Regional differences in climate largely account for this variation. Other factors include altitude and the duration of snow cover.
The flora of Iceland includes only around 490 wild vascular plants. This is a far smaller number than in either mainland Scandinavia or the British Isles. The main reasons for this comparatively low number of species are (a) the relatively short length of time that has passed since glacier ice covered most of Iceland, (b) Iceland’s isolation, and (c) the limited opportunities for species to reach Iceland. Most experts believe that all species growing in Iceland arrived after the Ice Age, while others think that as much as a fifth of Iceland’s flora survived the Ice Age.
Our knowledge of Icelandic plantlife is quite good. Over 1,500 different wild species have been documented in Iceland, and their distribution is quite well known. Species composition varies somewhat from region to region, as the climate differs between them. Some regions have an oceanic climate, while other areas are characterised by lower oceanity. Temperature, snow cover, and height above sea level are all also important factors. Given Iceland’s size, however, the difference between the flora of different regions is much less than might be expected.
New species arrive regularly in Iceland, brought here either by the wind or with birds and humans. Humans have introduced many species to Iceland over the years, either intentionally or by accident. Various species now present in the wild were originally brought to Iceland as garden plants. In nature, these introduced species sometimes become invasive.
Another resource on the flora of Iceland (in Icelandic only) is Flóra Íslands, which contains fact sheets on around a thousand Icelandic plant species.
Eyþór Einarsson 2005. Flóra og gróður Íslands. In Hans H. Hansen. Íslandsatlas, pp. 18–23. Reykjavík: Edda.