Nerine is a genus of about 20–30 species of bulbous perennial flowering plants in the family Amaryllidaceae (subfamily Amaryllidoideae), native entirely to southern Africa. The genus was established by the Reverend William Herbert in 1820, and today is placed firmly within Amaryllidaceae rather than the true lily family Liliaceae, to which it is only distantly related.
Plants are herbaceous bulbous perennials, with some species evergreen and others deciduous. Leaves range from narrow and filiform (thread-like), as in Nerine filifolia, to broad and strap-shaped. A distinctive feature of the deciduous species is hysteranthy: the flowers emerge on bare, leafless scapes before the foliage appears. Flowers are carried in spherical umbels and are lily-like in appearance, each consisting of six narrow, undulate (wavy) tepals with crisped margins in shades from white through pink to deep crimson. The six stamens and slender style typically protrude conspicuously from the flower. The inferior ovary is trilocular and matures into a dry loculicidal capsule; seeds are often viviparous, beginning to germinate before dispersal. Chromosome number is typically 2n=22.
The approximately 24–25 accepted species are organised into five groups based on leaf width, deciduousness, pedicel characteristics, and genome size. All are native to southern Africa, from the Cape Peninsula northward through all nine provinces of South Africa to Botswana, Eswatini, Lesotho, and Namibia, favouring rocky, arid, and mesic habitats. Most species occur in the summer-rainfall zone, where three growth strategies exist: winter-growing, summer-growing, and evergreen.
Nerines are well known in horticulture, with Nerine bowdenii and N. sarniensis being the most widely cultivated. N. sarniensis, the Guernsey lily, has been grown in Europe since the early seventeenth century and is the national flower of Guernsey. Several species and numerous hybrids are grown commercially as cut flowers, valued for vase life of up to 14 days. Several evergreen species—including N. masoniorum and N. gibsonii—are critically threatened in the wild due to habitat loss and overgrazing, and are maintained in ex situ collections at the Kirstenbosch National Botanical Garden.
Etymology
The genus name Nerine was given by William Herbert in 1820 and derives from the Nereids, the sea-nymphs of Greek mythology believed to protect sailors and ships. Herbert drew on Robert Morison's seventeenth-century account of N. sarniensis bulbs washing ashore from a shipwreck off Guernsey, combining it with an allusion to the rescue of Vasco da Gama's fleet by a Nereid in Camões' epic poem Os Lusíadas. An earlier genus name, Imhofia (Heister, 1755), was formally rejected in favour of the widely adopted Nerine.
Distribution
Nerines are native exclusively to southern Africa, with their range extending from the Cape Peninsula in the southwest through all nine provinces of South Africa to Botswana, Eswatini, Lesotho, and Namibia. Most species are concentrated in the summer-rainfall region of South Africa and favour rocky, arid, or mesic habitats, including mountainous terrain.
Ecology
Nerine species fall into three distinct growth strategies—winter-growing, summer-growing, and evergreen—reflecting the varied seasonal rainfall regimes across their range. Flower colour shows ecological significance: the red-flowered forms are adapted to pollination by the mountain pride butterfly (Aeropetes tulbaghia), while pink-flowered species are associated with other pollinators.
Cultivation
Breeding and hybridisation of nerines began in the early nineteenth century with William Herbert, who raised and described seven hybrids. Nerine sarniensis has been cultivated in Europe since the early 1600s, and N. bowdenii was introduced to England at the end of the nineteenth century. Today, several species and many hybrid cultivars are grown as ornamentals and commercially as cut flowers, with blooms lasting up to 14 days in water. Bulbs require a minimum of two years of growth before flowering. The hybrid cultivar 'Zeal Giant' has received the Royal Horticultural Society's Award of Garden Merit.
Conservation
Several Nerine species face serious conservation pressure from habitat loss and degradation. Nerine masoniorum is considered critically threatened—possibly extinct in the wild—after its only known colony site was developed for housing. Nerine gibsonii is endangered by overgrazing and erosion in its Eastern Cape grassland habitat. Ex situ conservation of N. filamentosa, N. gibsonii, N. gracilis, N. huttoniae, and N. masoniorum is maintained at the Kirstenbosch National Botanical Garden. Some species, such as N. platypetala, are protected within nature reserves.
