Cape buttercup (Sparaxis elegans)

Description

Cape buttercup fact file

• Description
• Biology
• Range
• Habitat
• Status
• Threats
• Conservation
• Find out more
• Glossary
• References
• Print factsheet

Cape buttercup description

This attractive perennial plant is recognised by its distinctively patterned flowers, and by the flower’s coiling anthers, which are twisted around the style ⁽⁵⁾. Each stem bears up to five symmetrical flowers, which measure around four centimetres in diameter and have six petal-like tepals, with a short funnel-shaped tube at the centre. The flowers of Sparaxis elegans come in various shades of red, orange, salmon-pink or sometimes white, marked with yellow or purple ^{(2) (3) (5)}, and have a ring of distinctive yellow and black markings near the centre. One of the most striking features of Sparaxis species is the floral bracts, which are dry, papery, and pale in colour, with brown streaks ^{(5) (6)}. Sparaxis elegans produces a fan of somewhat fleshy, pale green, lance-shaped leaves from an underground storage organ known as a corm ^{(1) (2) (3) (5) (6)}.

Also known as

pale harlequin flower.

Synonyms

Streptanthera cuprea, Streptanthera elegans.

Size

Height: 10 - 30 cm ^{(2) (3)}

Cape buttercup biology

Sparaxis elegans is a perennial species, producing flowers annually between August and September, during or soon after the main rainy season ⁽³⁾. The flowers are bisexual (contain both male and female reproductive parts) ⁽¹⁾, and are pollinated by scarab beetles and tabanid flies ^{(3) (7)}. Intriguingly, the distinctive dark marks on the flowers, known as “beetle marks”, are believed to serve to attract its beetle pollinators ^{(6) (7) (8)}. As in other Sparaxis species, the fruit is a capsule, which contains an average of 24 to 30 spherical, hard, shiny brown seeds ^{(1) (5) (6)}.

Cape buttercup range

Sparaxis elegans is endemic to the Cape Floristic Region in the western Cape Province of South Africa, where it occurs in the Bokkeveld Plateau in the northwestern Cape, extending southward some 25 kilometres from Nieuwoudtville. The more common salmon-pink form is typically found in the Nieuwoudtville area, while the white-flowered form occurs in the south of the range, sometimes mixed with the pink ⁽⁵⁾.

Cape buttercup habitat

Sparaxis species are restricted to the winter-rainfall region of southern Africa, with this species usually growing in light to heavy clay soils ^{(5) (6)}.

Cape buttercup status

Classified as Vulnerable (VU) on the Red List of South African Plants ⁽⁴⁾.

Cape buttercup threats

Sparaxis species have long been valued as garden and indoor plants due to their bright and colourful blooms, and many hybrids have been created ^{(1) (6)}. However, the impacts on the wild population of Sparaxis elegans are unknown. The greatest threat to this species is the loss and alteration of its habitat. The species occurs in nutrient-rich clay soil which is the most productive agricultural land on the Bokkeveld Plateau, and more that 70 percent of its habitat has already been converted for crop cultivation. Six populations remain in fragments which are only marginally suited to cultivation, and are not currently declining. However, sporadic ploughing of natural vegetation for new crop fields still occurs, and habitat loss remains a potential threat ⁽⁹⁾.

Cape buttercup conservation

The Cape Floristic Region is considered a global hotspot for biodiversity and is designated as a Global Centre of Plant Diversity and a World Heritage Site. As such, it is one of the most intensely researched floral regions in the world, with a number of conservation initiatives in place, and also contains a number of National Parks and protected areas ^{(10) (11)}. Although these are not considered totally representative of the region’s full biodiversity ⁽¹⁰⁾, they may go some way towards helping protect Sparaxis elegans populations. Conservation initiatives underway in the region include the Working for Water Programme, which is attempting to remove alien plants, encourage the regeneration of natural vegetation, and protect watersheds ^{(10) (12)}, and one population of Sparaxis elegans is also protected in the Nieuwoudtville Wildflower Reserve ⁽⁹⁾. With measures such as these, and a high level of interest and attention in the region, this striking plant will hopefully face a brighter future.

Find out more

For more information on South African plants see:

• PlantZAfrica:
  http://www.plantzafrica.com/

• Conservation International: Biodiversity Hotspots - Cape Floristic Region:
  http://www.biodiversityhotspots.org/xp/hotspots/cape_floristic/Pages/default.aspx
• Biodiversity and Wine Initiative:
  http://www.bwi.co.za/index.asp
• UNEP-WCMC: Cape Floral Region Protected Areas, Western Cape and Eastern Cape Provinces, South Africa:
  http://www.unep-wcmc.org/medialibrary/2011/06/29/2823bc8a/Cape%20Floral.pdf

Authentication

Authenticated (06/07/10) by Lize von Staden, Red List Scientist, Threatened Species Programme, South African National Biodiversity Institute, Pretoria, South Africa.
http://www.sanbi.org/

Glossary

Anther

Part of the stamen (the male reproductive organ of a flower) that produces pollen.

Bract

Modified leaf at the base of a flower.

Cape Floristic Region

An area occupying about 90,000 square kilometres in South Africa that contains an incredibly high diversity of plant species (around 8,700 species), of which 68 percent are found no where else.

Corm

A short swollen stem, which develops at ground level or below ground and has a storage function.

Endemic

A species or taxonomic group that is only found in one particular country or geographic area.

Hybrid

The offspring produced by parents of two different species or subspecies.

Perennial

A plant that normally lives for more than two seasons. After an initial period, the plant produces flowers once a year.

Pollination

The transfer of pollen grains from the stamen (male part of a flower) to the stigma (female part of a flower) of a flowering plant. This usually leads to fertilisation, the development of seeds and, eventually, a new plant.

Pollinator

An animal that in the act of visiting a plant’s flowers transfers pollen grains from the stamen (male part of a flower) to the stigma (female part of a flower) of a flowering plant. This usually leads to fertilisation, the development of seeds and, eventually, a new plant.

Style

An elongated part of the female reproductive organs of a flower that bears the stigma (the receptive area where pollen germinates), usually at its tip.

Tepal

Element of the outer part of a flower (the perianth), which includes the petals and sepals (floral leaves). The term is usually used when the segments of the perianth are undifferentiated or are indistinguishable as petals or sepals.

References

1. Heywood, V.H. (1978) Flowering Plants of the World. Oxford University Press, Oxford.
2. Ellis, B.W. (2001) Taylor’s Guide to Bulbs: How to Select and Grow 480 Species of Spring and Summer Bulbs. Houghton Mifflin Company, New York.
3. Goldblatt, P., Manning, J.C. and Bernhardt, P. (2000) Adaptive radiation of pollination mechanisms in Sparaxis (Iridaceae: Ixioideae). Adansonia, 22(1): 57-70.
4. Raimondo, D., Von Staden, L., Foden, W., Victor, J.E., Helme, N.A., Turner, R.C., Kamundi, D.A. and Manyama, P.A. (2009) Red List of South African Plants. Strelitzia 25. South African National Biodiversity Institute, Pretoria.
5. Goldblatt, P. (1992) Phylogenetic analysis of the South African genus Sparaxis (including Synnotia) (Iridaceae-Ixioideae), with two new species and a review of the genus. Annals of the Missouri Botanical Garden, 79(1): 143-159.
6. Goldblatt, P. and Manning, J.C. (2008) The Iris Family: Natural History and Classification. Timber Press, Portland, Oregon.
7. Goldblatt, P., Bernhardt, P. and Manning, J.C. (1998) Pollination of petaloid geophytes by monkey beetles (Scarabaeidae: Rutelinae: Hopliini) in southern Africa. Annals of the Missouri Botanical Garden, 85(2): 215-230.
8. Van Kleunen, M., Nänni, I., Donaldson, J.S. and Manning, J.C. (2007) Role of beetle marks and flower colour on visitation by monkey beetles (Hopliini) in the Greater Cape Floral Region, South Africa. Annals of Botany, 100: 1483-1489.
9. Von Staden, L. (July, 2010) Pers. comm.
10. Conservation International: Biodiversity Hotspots - Cape Floristic Region (January, 2010)
    http://www.biodiversityhotspots.org/xp/hotspots/cape_floristic/Pages/default.aspx
11. UNEP-WCMC: Cape Floral Region Protected Areas, Western Cape and Eastern Cape Provinces, South Africa (January, 2010)
    http://www.unep-wcmc.org/medialibrary/2011/06/29/2823bc8a/Cape%20Floral.pdf
12. Department of Water Affairs, Republic of South Africa: Working for Water (January, 2010)
    http://www.dwaf.gov.za/wfw/