New Zealand has evolved a unique flora due to long-term isolation from other large landmasses. Approximately 80 per cent of the 6,700 native plant species are found only in New Zealand. Compared to other temperate floras, New Zealand has fewer species adapted to cold, fire, or browsing by mammals. Due to a lack of a strongly seasonal climate, most vascular plants are perennial evergreens. Flowers are typically small and white, and produce strong scents to attract a wide variety of pollinators. New Zealand has an unusual number of ferns for a temperate country, approximately 200 species. An uncurling fern frond (‘koru’ in te reo Māori) is a common motif in design, and the silver fern (Cyathea dealbata) is a widely recognized symbol of New Zealand. Other iconic plant species include the kowhai (Sophora sp.), a popular garden tree with bright yellow flowers, and the pohutukawa (Metrosideros excelsa), also known as the New Zealand Christmas tree due to brilliant red blooms in December.

Prior to Māori arrival, most of New Zealand was covered in dense forest, colloquially known as ‘the bush’. Through the combined efforts of Māori land clearance and the early European timber industry, less than half of the original forest remained by the mid-1800s. Kauri (Agathis australis), a coniferous tree found on the north of the North Island, was a highly sought-after wood for construction due to its length (growing up to 50 m), light weight, straight grain, and beautiful colours. Other commercially important trees in the early timber industry included rimu (Dacrydium cupressinum), totara (Podocarpus totara), and kahikatea (Dacrycarpus dacrydioides). As the supply of native trees diminished, forestry turned to fast-growing non-natives such as Monterey pine (Pinus radiata), which was introduced from California in 1859 and now covers 6 per cent of New Zealand’s total land area. Approximately one-quarter of New Zealand remains forested by native tree species, predominantly southern beech forests in cooler environments and podocarp-broadleaf forests elsewhere.

Māori made extensive use of native plants for all aspects of daily life. Common species such as flax (Phormium sp.) were used for multiple functions, including clothing, rope, and medicine. More than 200 species were used medicinally by Māori; for example, the leaves and bark of kawakawa (Piper excelsium) were used to treat cuts and stomach aches. Crop species (kumura, taro, hue, and uwhi) were brought to New Zealand by Māori from their Pacific Islands of origin. To modern times, essentially all plant species cultivated for food have been imported. An estimated 25,000 non-native plant species have been introduced to New Zealand, mainly for gardening or farming, of which 1,800 have become naturalized. Some non-native species, such as gorse and blackberry, are widespread and difficult to control. Introduced pests and pathogens, as well as weeds and habitat destruction, are the leading threats to New Zealand’s native flora. Approximately 30 per cent of the native flora is considered at risk of extinction from either specific threats or naturally small population sizes.