Cape bugle-lily (Watsonia borbonica)

Synonyms: Watsonia ardernei, Watsonia pyramidata
GenusWatsonia (1)
SizeHeight: up to 2 m (2)

This species has yet to be classified by the IUCN.

The Cape bugle-lily is an attractive herbaceous plant, with strikingly coloured, trumpet-shaped flowers, that grows within the unique and diverse fynbos habitat of the Cape Floristic Region. The broad, pointed green leaves give the base of the plant a fan-like appearance, and surround an elongated vertical flower spike, which bears up to 20 flowers. The large ornate flowers vary in colour, from pale to light purple, and have a slight scent. The fruit of the Cape bugle-lily is an egg-shaped, woody capsule, which contains many small, oblong winged seeds (2) (3).     

The Cape bugle-lily is native to the Cape Floristic Region, South Africa, and has been introduced into parts of Australia, California, Hawaii and Mexico (2) (4). 

The Cape bugle-lily grows amongst fynbos shrubland, where it is most abundant on rocky sandstone soils, or well-drained granite, clay and sandy soils on mountain slopes, up to an altitude of 1,000 metres above sea level (2) (5). 

The Cape bugle-lily is a perennial plant that flowers between October and December (6). It is a deciduous species, and will grow through autumn, winter and spring, before dying back after flowering, and remaining dormant in the summer. After natural fires, which kill much of the above ground vegetation, dense stands of the Cape bugle-lily often sprout from underground stem swellings bearing vegetative buds. Flowers subsequently appear on the new shoots, and large solitary bees, which are attracted by the sweet, sugar-rich nectar, are the main pollinators. Following pollination, a mass of seeds are produced, which are dispersed across the landscape by the wind (2).    

The Cape bugle-lily is restricted to the botanically rich habitat of the Cape Floristic Region where conservation is now a high priority. Substantial areas of this region have previously been lost through urbanisation, and habitat conversion for agriculture and commercial plantations. Around urban areas, the natural fires, upon which fynbos plants are dependant for reproduction, are suppressed, reducing many species’ ability to reproduce, while wetlands may be drained and groundwater extracted (2).  

Although relatively restricted in range, dense stands of the Cape bugle-lily remain in some places, and it is currently not considered threatened. However, the subspecies W. b. ardeneri has an extremely limited distribution, and due to continuing threats, it is listed as Vulnerable on the South African Interim Red Data List (7). 

In Australia, the Cape bugle-lily is considered an environmental weed, as its ability to reproduce quickly and persist in arid regions, allows it to out-compete native species for nutrients and space. The species is actively eradicated using chemical pesticides, machinery, livestock grazing and by limiting the species dispersal (3). 

Conservation measures currently being undertaken in the Cape Floristic Region include the restoration of the landscape to its natural state, through the burning and cutting of non-native plants, and the purchasing of land to protect against the threats of encroaching urban development and agriculture (8) (9). At present, only a small proportion of the Cape Floristic Region lies in reserves, and many of the protected areas are privately owned, with the level of protection provided variable. To ensure the preservation of Cape bugle-lily populations, a larger network of protected areas should be established with greater connectivity between reserves (8). In addition, the conservation organisation Fauna and Flora International are coordinating projects that promote ecologically and financially sustainable cultivation of fynbos plants to provide long-term, community directed protection of the fragile ecosystem (9).

For more information on the Cape Floristic Region and its conservation, see:

For more information on African plants, see:

Authenticated (15/05/2010) by John Manning, Research Botanist, South African National Biodiversity Institute, Kirstenbosch, South Africa.

  1. ITIS (January, 2010)
  2. PlantZ Africa (January, 2010)
  3. Department of Primary Industries Information Notes: Wild Watsonia (January, 2010)
  4. Global Biodiversity Information Facility (January, 2010)
  5. Goldblatt, P. (1987) Notes on the variation and taxonomy of Watsonia borbonica (W. pyramidata, W. ardernei) in the southwestern cape, South Africa. Annals of the Missouri Botanical Garden, 74: 570-572.
  6. SANBI’s Integrated Biodiversity Information System (January, 2010)
  7. Interim Red Data List of South African Plant Taxa (January, 2010)
  8. Cowling, R. and Richardson, D. (1995) Fynbos: South Africa’s unique floral kingdom. Fernwood Press, South Africa.
  9. Fauna and Flora International (January, 2010)