Look-alikes: how to tell Kidney Weed (Dichondra repens) and its look-alikes apart

Are you struggling to tell you Kidney Weed from your Gotu Kola? Have you got some unfamiliar round-leaves plants growing in your lawn, and want help working out what they are? If so this post is for you! Elena Martinez from the Growing Illawarra Natives team recently provided a practical and well-illustrated guide to Kidney Weed and its look-alikes on the Growing Illawarra Facebook page. I've adapted Elena's post for the Growing Illawarra Natives blog. 

Kidney Weed, Dichondra repens, also known as Dichondra, is a locally common low-growing ground-cover that forms dense mats in suitable conditions. NSW PlantNET gives its Dharawal language name as yilibili. Dichondra's natural distribution is wide and it occurs in every state and territory apart from the Northern Territory. It is also widely cultivated and used in gardens and landscaping, being one of the most regularly seen ground cover species across coastal eastern Australia and south-west Western Australia. It's a low-maintenance option for a wide range of garden situations, and easily sourced. 

This is Kidney Weed (Dichondra repens) growing in a natural area in wet sclerophyll forest. Image by Emma Rooksby. 

One of the most common look-alikes is another native species, Gotu Kola or  Centella asiatica. It has a distinctive V- shaped gap where the stem meets the leaf, as the image below shows. It also indicates how tall Gotu Kola can grow. Both species can root from nodes on their stems, meaning a patch of either species usually has many separate sets of roots. Those of Gotu Kola are more robust and fleshier than those of Dichondra.

This image shows Gotu Kola growing densely up against a brick wall. The distinctive v-shaped gap where the leaf stem (petiole) meets the leaf surface (lamina) is a good way to tell this species from Dichondra. Image by Elena Martinez.

When seen side by side, it's easier to pick the differences between Gotu Kola (Centella asiatica), shown on the left, and Kidney Weed (Dichondra repens), on the right. 

Here you can see Centella asiatica on the left, Dichondra repens on the right. Dichondra has minute hairs on upper and lower surface, so feels hairy; the leaf curves back towards the stem. You can clearly see the v-shaped gap in the leaf of the Centella. The difference in height and size of the leaves is also quite evident in this picture. Image by Elena Martinez. 

An introduced species that can be confused with both of these local species, especially when it's not in flower, is the Red-flowered Mallow Modiola caroliniana, which comes from Southern America and is now widespread in gardens across NSW and beyond. It has orange flowers, which when present make it easy to distinguish from Dichondra and Centella, which have small, inconspicuous yellow-green or yellow-white flowers. 

Red-flowered Mallow's leaves are ovate to broad-ovate. This contrasts with Centella, whose leaves are more or less round, and Dichondra, which has renate or kidney-shaped leaves. Red-flowered Mallow leaves also have three to seven toothed lobes, though these are not always deeply lobed. Image by Elena Martinez. 

 Like Dichondra and Centella, Red-flowered Mallow's stems root at the nodes. This makes removal difficult as every portion with roots needs to be removed. 

Stems of Red-flowered Mallow, showing its low-growing character. You can more or less glimpse some nodes with roots running across more or less the centre of the image. Image by Elena Martinez. 

A couple of other fairly common local native look-alikes include the Native Violet Viola hederacea, and two species of Pennywort, Hydrocotyle peduncularis and H. tripartita. 

Native Violet Viola hederacea has distinctive white and purple flowers and smooth (glabrous) leaves, which can be used to tell it apart from Dichondra which has those minute hairs on both surfaces of the leaf lamina. Image by Elena Martinez. 

The leaves of this Pennywort (Hydrocotyle peduncularis) are soft, broad and many-lobed, around 2cm wide and shaped like little fans. The lobes are generally fairly shallow, and are sometimes more or less absent. The upper and lower surfaces of the leaves are hispid, meaning they are covered by little bristles. Image by Elena Martinez. 

The leaves of this Pennywort (Hydrocotyle tripartita) are generally round in outline, but divided into three-five segments each of which is more or less deeply lobed. This groundcover establishes itself in suitable conditions, preferring damp part shaded conditions and clay soils. Image by Keith Horton.  

Elena, who has many years experience gardening with local natives, suggests that Dichondra repens is the best ground cover in the shade if you are used to mown lawn, so don't want anything too tall. It will tolerate light to moderate foot traffic but isn't suitable for heavy use. Try mixing it with some of the other native ground covers featured in this post and see which ones prevail. Happy ID'ing and growing!