Scadoxus is a genus of approximately nine species of bulbous and rhizomatous flowering plants native to sub-Saharan Africa and the Arabian Peninsula, belonging to the family Amaryllidaceae (subfamily Amaryllidoideae) within the order Asparagales. The genus is commonly known as blood lily or blood flower, names that allude to the vivid scarlet and crimson hues of the flower heads.
Plants grow from bulbs or rhizomes — sometimes both — and produce lanceolate to ovate leaves with a thickened midrib. In the non-bulbous species, overlapping leaf-stalks (petioles) form a distinctive false stem, or pseudostem, which is often marked with purple spots. The leafless flowering scape rises from among the leaves or pushes through the side of the pseudostem and bears a dense, many-flowered umbel at its apex. Individual flowers have six red to pink tepals fused at the base into a short tube, with prominent stamens extending beyond the petals. After flowering, round, fleshy berries ripen to orange or red.
The genus is closely related to Haemanthus and was formally named in 1838 by Constantine Samuel Rafinesque. Nine species are accepted, ranging from widespread tropical African species to narrow endemics confined to single mountain ranges. Scadoxus multiflorus is the most widely distributed, occurring throughout tropical and southern Africa and into the Arabian Peninsula; it is also the most commercially cultivated, grown in quantity by the Dutch nursery industry. Scadoxus puniceus, found in South Africa, and S. cinnabarinus of West and Central Africa are also well known.
Most species inhabit tropical forests, growing in warm, moist, shaded conditions in soil or, in the case of some species, as epiphytes. The three South African species tolerate cooler, drier conditions. All species are grown as ornamentals for their spectacular flowerheads, either in containers or in the ground in frost-free climates. The genus is toxic: all species contain poisonous alkaloids lethal to grazing animals, and several — including S. multiflorus and S. cinnabarinus — have been used in traditional African medicine and as components of arrow and fishing poisons.
Etymology
The name Scadoxus was coined in 1838 by Constantine Samuel Rafinesque. The element doxus derives from the Greek for "glory" or "splendour", referring to the often-scarlet flowers of the genus. The prefix sca- is thought to derive from the Greek skia ("shade"), as sciadon was the Greek equivalent of the Latin umbella — both terms used for umbrella-shaped flower heads — alluding to the umbel form of the inflorescence.
Distribution
Scadoxus is distributed across sub-Saharan Africa and the Arabian Peninsula, with Scadoxus multiflorus being the most wide-ranging species, present throughout tropical and southern Africa and as the sole representative of the genus in the Arabian Peninsula. The genus has been introduced to parts of Mexico. Most species occur in tropical forests, growing in warm, moist, shaded conditions either in soil or as epiphytes. The three species native to temperate South Africa — S. multiflorus, S. puniceus, and S. membranaceus — are more bulbous in habit and tolerant of drier, cooler conditions; S. puniceus has even been recorded on sand dunes and dry cliff faces.
Cultivation
All Scadoxus species occur naturally in areas of summer rainfall and in cultivation tend to begin growth in spring following winter dormancy. The three South African species (S. multiflorus, S. puniceus, and S. membranaceus) are the most widely cultivated, tolerating winter temperatures as low as 5 °C (41 °F). Tropical species require a minimum of 10 °C (50 °F) and a warm, humid atmosphere. An open, organic potting medium with good aeration — similar to orchid mix — suits all species; this is especially important for epiphytic species such as S. nutans. Common pests in cultivation include mealy bugs, narcissus bulb fly (Merodon equestris), red spider mites, and slugs; in South Africa, lily borer (Brithys crini) is also a threat.
Cultural Uses
Several Scadoxus species have been used in traditional African medicine despite their toxicity. Scadoxus multiflorus and Scadoxus cinnabarinus are used in parts of tropical Africa as components of arrow poisons and fishing poisons. Scadoxus puniceus is similarly used in traditional medicine in South Africa. The poisonous alkaloids responsible for the toxicity are lethal to grazing animals such as sheep and goats.
