© Colin Paterson Jones
This plant, a true fire lily, defies the elements by producing its beautiful, salmon to scarlet blooms just nine days after the seemingly destructive effects of fire.
Cyrtanthus ventricosus is a deciduous, bulbous plant reaching 100–250 mm tall. Each winter the plants produce a tuft of linear leaves, 2–7 mm wide, which die back as the dry summer season approaches.
The inflorescence, which appears within two weeks after a summer fire, has a 100–200 mm tall, hollow scape with a terminal cluster of 1–12 narrowly trumpet-shaped, nodding flowers, 40–50 mm long. The pale to dark salmon or crimson flowers have a contrasting, darker crimson band on the midrib of each tepal (a member of the perianth that is not clearly differentiated into calyx or corolla). They are unscented and produce nectar which collects at the base of the tube. The six stamens are arranged in two whorls in which the outer filaments are somewhat longer than the inner. The anthers split open one to two days after the flower opens and then the three short lobes of the stigma become receptive a few days later. Each flower remains open for approximately five to six days then finally loses turgor, becomes narrowly tubular and turns dull red. Individual plants in the population flower more or less at the same time and the entire flowering period lasts approximately two weeks.
The three-chambered, inferior ovary, which has 40–60 ovules, develops into a capsule which takes about seven weeks to mature. Like all other Cyrtanthus species, the seeds are dry, black, flattened and winged.
© Colin Paterson Jones
According to the most recent Red Data assessment, Cyrtanthus ventricosus is regarded as being of Least Concern since it faces no perceived threats to its future survival.
Distribution and habitat
Cyrtanthus ventricosus is found along the Cape Fold Mountains from the Cape Peninsula, Western Cape, to the Kouga Mountains, Eastern Cape, in association with fynbos. Populations vary in size from less than a hundred to a thousand or more individuals which are confined to south-facing slopes in sandstone-derived soil. Unlike the majority of individuals which have crimson flowers, those on the Cape Peninsula are salmon-coloured with dark crimson bands on the tepals.
Derivation of name and historical aspects
The name Cyrtanthus means ‘curved flower' a feature often associated with the flower's nodding habit. The species epithet, ‘ ventricosus ' means ‘swollen' and refers to the somewhat enlarged perianth tube of the flower.
With about 50 species, Cyrtanthus is the largest genus of Amaryllidaceae in southern Africa. The genus extends from as far north as East Africa, where there are only two species, southwards along the eastern parts of southern Africa to the Cape Peninsula in the extreme southwest. Twenty-four species are found in the Greater Cape Floristic Region, many of which are rare or rarely seen. In contrast, the southeastern region of South Africa is home to the highest concentration of species. The genus shows the greatest floral diversity of all African members of Amaryllidaceae, probably due to the plants having become adapted to different pollinators—bees, birds, butterflies, moths and long-tongued flies. Remarkably, C. ventricosus, together with several other species in the genus, are entirely dependent on fire to flower. The flowers typically appear within little over a week after fire after which the plant remains in a vegetative state, sometimes for intervals lasting 15 years or more.
Unique to this and many other Cyrtanthus species is the hollow scape which is structurally strong and light on resources for its development. In effect, the hollowness of the scape may be key to enabling the plant to put forth flowers so promptly after fire. Aeropetes tulbaghia, the Table Mountain Pride butterfly, frequently visits the flower heads of C. ventricosus.
© Colin Paterson Jones
The butterfly alights on top of the flower and extends its long proboscis between the upper tepals to reach the nectar at the base of the tube. While doing so the proboscis occasionally brushes against the anthers and style, which arch against the upper tepals, thereby transferring pollen from one plant to another. Sunbirds are also frequent visitors and are known to pierce holes at the base of the flower for nectar. In this way they ‘rob' the reward offered by the flower without contributing to its fertilisation. The anthers release pollen a day or two after the flower opens and a few days later the stigma becomes receptive, ensuring that outcrossing is achieved. Unlike several other species in the genus, C. ventricosus does not reproduce vegetatively by offsets from the bulb. The species is propagated only from seeds which are flattened and somewhat winged, and admirably suited to dispersal by wind.
Uses and cultural aspects
Cyrtanthus ventricosus provides wonderful floral displays during its brief flowering period after summer fires. Through its ‘phoenix-like' habit it is a source of interest and wonder, especially when seen in the wild against a blackened, ash-strewn backdrop. The plant's total dependence on fire, however, makes it unrewarding for cultivation.
© Colin Paterson Jones
Growing Cyrtanthus ventricosus
In general Cyrtanthus species from the dry areas of the Cape are difficult to grow and easily succumb to overwatering . They are best grown in pots which can be kept dry in summer and allow for the provision of good drainage, a necessity for successful cultivation. The seeds of Cyrtanthus have a short period of viability and are best sown as soon as they are harvested. As a true fire lily, C. ventricosus is best left to grow in the wild.
References and further reading
- Duncan, G.D. 1990. Cyrtanthus – its horticultural potential. Part 1. Veld & Flora 76: 18–21.
- Leistner, O.A. (ed.). 2000. Seeds plants of southern Africa : families and genera. Strelitzia 10. National Botanical Institute, Pretoria .
- Manning, J, Goldblatt, P. & Snijman, D. 2002. The Color Encyclopedia of Cape Bulbs. Timber Press, Portland.
- Raimondo, D., Von Staden, L., Foden, W., Victor, J.E., Helme, N.A., Turner, R.C., Kamundi, D.A. & Manyama, P.A. (eds). 2009. Red List of South African plants. Strelitzia 25. South African National Biodiversity Institute, Pretoria.
- Smith, C.A. 1966. Common names of South African plants. Memoirs of the Botanical Survey of South Africa No. 35.
- Snijman, D.A. & Meerow, A.W. 2010. Floral and macroecological evolution within Cyrtanthus (Amaryllidaceae): Inferences from combined analyses of plastid ndh F and nrDNA ITS sequences. South African Journal of Botany 76: 217–238.
- Snijman, D.A. 2012. Amaryllidaceae. In J. Manning & P. Goldblatt, Plants of the Greater Cape Floristic Region 1: the core Cape flora. Strelitzia 29. South African National Biodiversity Institute, Pretoria.
Colin Paterson-Jones (copyright).