Weed of the Month – October 2016

HOTTENTOT FIG

(Carpobrotus edulis)

edulis-composite

(Photos: C. Schultz, Cape Jervis, Yellow flowers, ‘teeth’ on leaves and possible hybrid flower)

At first glance, you might think this groundcover is our native pigface, Karkalla. There is that triangular cross-section of the succulent leaves,but this one has ‘teeth’, or a rough edge, to the sharper side, whereas Karkalla is smooth. Its large yellow flowers are the biggest giveaway to its identification though. Unlike our local pink-flowered pigface, this is an invasive introduced species …in fact, it is so invasive it is listed in the Invasive Species Database for 24 countries! Unfortunately, the plant hybridizes with the local pigfaces, where they come into close proximity, and this leads to other problems e.g. swamping local species genetically. One particular concern is that Karkalla is a food source. Although the hottentot fig is also edible, what happens with the hybrids?

Plant of the Month – October 2016

KARKALLA
(Carpobrotus rossii)

Microsoft Word - PLANT OF THE MONTHoctober16_carpobrotus_rossi.d
(Photos : C. Schultz)

This S.A. member of the pigface family is probably well-known to you all. The triangular cross-section of the succulent leaves is a bit of a giveaway, as are those bright pink flowers you see standing out on the edges of sandy beaches. You might notice a difference in some flowers. This is because there are both male and female forms. The male form at up to 6 cm across is larger than the female one, and has stigmas fused into a central column. The stigmas of the female flower, though, are open and recurved in the centre. As well as binding sandy soil the plant has other uses: the fruit and leaves were an indigenous food source, and the juice from those fleshy leaves has been used to soothe problems such as blisters, burns and stings…even scurvy! Way to go, Karkalla!!