Cotula turbinata is a pretty, early flowering annual that can be seen popping up in grassy patches along sidewalks and other moist open places throughout the Western Cape in late winter and early spring.
This is a soft annual herb, 150–300 mm tall; leaves alternate, finely divided. Flower heads solitary, 4–12 mm wide; peduncle becoming prominently inflated apically in fruit; bracts in 2 rows, 3–5-nerved. Florets of three types: (1) the outermost series of disciform florets which lack a corolla and are borne on long pedicels, (2) an adjacent series of ray-like florets with the outermost of the four lobes greatly elongated, and (3) inner series of four-lobed disc florets. The ray-like florets are usually white, although they can sometimes be yellow. The disc florets are either white or more commonly yellow. Flowering time: July to October.
Cotula turbinata is a widespread and relatively common species and as a result is characterized as LC (Least Concern) (Foden & Potter 2005).
Distribution and habitat
Cotula turbinata is endemic to the winter-rainfall region of South Africa and occurs from the Cedarberg Mountains to Cape Town and eastwards to De Hoop (Manning & Goldblatt 2012). The species occur mostly in disturbed and/or sandy areas and as a result is often found in mass along grassy road verges and park lawns.
Derivation of name and historical aspects
Cotula turbinata was first described by Linnaeus in 1753. This species, together with several others, was subsequently treated under the genus Cenia (Persoon 1807) based on their distinctive inflated peduncle apices. This distinction is, however, no longer recognized and the species are again treated under the large and complicated genus Cotula (± 50 species) (Levyns 1941; Manning & Goldblatt 2012 ).
The species epithet turbinata refers to this spinning-top or inverted, cone-shaped, apically inflated peduncle.
The function of the distinctive, apically inflated peduncle is uncertain. The inflation is hollow and is at its largest when the head is fruiting. As such, it is likely to have a function in seed dispersal, possible acting as a shaker in the wind.
As mentioned in the description there are three types of florets present in the heads of Cotula turbinata (and allied species, viz. C. duckittiae and C. discolor ). The most distinctive are the ray-like florets. In C. turbinata , the second row of disc florets are modified so that the outermost of the four lobes is greatly elongated giving the head the appearance of being radiate. These are unlike typical ray florets which usually comprise the outermost series and which have all the lobes fused into a single, petal-like limb.
Growing Cotula turbinata
Cotula turbinata can be sown in your lawn for an attractive wildflower meadow effect (possibly together with Oxalis species) in winter or as filler between spring flowering bulbs.
Cotula turbinata can be easily propagated from seed planted in autumn. It should be placed in well-drained soil in an area that receives full sun, although it will tolerate partial shade. As C. turbinata is restricted to the winter-rainfall region of South Africa it will need regular watering throughout the winter and spring months, if grown outside of this region. Plants are likely to seed themselves in other parts of the garden once established.
References and further reading
- Bond, P. & Goldblatt, P. 1984. Plants of the Cape Flora: a descriptive catalogue. Journal of South African Botany , Suppl. 13.
- Foden, W. & Potter, L. 2005. Cotula turbinata L. National Assessment: Red List of South African Plants version 2014.1. Accessed on 2014/09/10.
- Levyns, M.R. 1941. Notes on Cotula and the Description of a New Species. The Journal of South African Botany VII: 131, 132.
- Lloyd, D.G. 1972. A revision of the New Zealand, Subantarctic, and South American species of Cotula , Section
- Leptinella New Zealand Journal of Botany 10: 2, 277–372, DOI:10.1080/0028825X.1972.10429156.
- Manning, J. & Goldblatt, P. 2012. Plants of the Greater Cape Floristic Region volume 1: The Core Cape Flora. Strelitzia 29: 365. South African National Biodiversity Institute, Pretoria. ISBN 978-1-919976-74-7.
Aarifah Jakoet and Anthony Magee