Similar but different in the south-west, a pair of Dasypogonaceae

I'm milking the last from my sprinter (August) visit to Western Australia with two plants that are not quite what they look like. You might think the top one is a grass tree, and the other is not unlike the Queen of Sheba sun orchid I featured a few weeks ago. They might also look like they are unrelated to one another, but it turns out they are, related.

What we have here are two members of the plant family Dasypogonaceae, Kingia and Calectasia. Kingia is the grass tree look alike and Calectasia a small shrub with the most vivid of flowers.

In the case of Kingia I'm reminded of John Lydon singing 'This is not a love song' back in 1983. In that case the ditty by Public Image Limited was pretty clearly not a love song. In this case Kingia is something we still might like to call a grass tree - it has the grassy bits atop a trunk of sorts.

But the 'true', 'typical' or 'usual' grass tree is Xanthorrhoea with its spear-like flower stalk rising well above the tufty leaves. Kingia has a few short pom-pom-like flower clusters rising not far above the leaves and is not botanically close to Xanthorrhoea. The favoured common name is simply Kingia or Bullanock (and never Black Gin which is quite sensibly, along with Black Boy for Xanthorrhoea, considered in appropriate and offensive today).

Bullanock is only found in the south-west while there are species of Xanthorrhoea in the east and west. Both grow here near Pemberton.

Calectasia is a more diverse genus than Kingia, although for a long time it was assumed there was only a single species. The flowers are usually purplish with a metallic sheath, offset by fingers of bright yellow clustered in the centre.

The flowers of Calectasia grandiflora (Tinsel Lily) and Thelymitra variegata (Southern Queen of Sheba orchid) are similar and the orchid may be mimicking the tinsel lily in an attempt to trick visiting insects into thinking it has nectar to offer (but not putting any energy into producing energy so pollinating by deception). Here is the lily and then the orchid, both photographed in the Stirling Range.

Kingia and Calectasia both resemble other, unrelated species. On the other hand, while it's difficult to find any similarities between the two of them they are in the same plant family, called the Dasypogonaceae. 'Dasypogon' means something like a hairy beard.

The Dasypogonaceae is an odd little family with four genera. Its namesake, Dasypogon, is a genus of three species from south-west Western Australia, with pom-pom like flower heads (in form not unlike those of Kingia).  Kingia has this one species, Kingia australis, only found in south-west.

Calectasia these days has 10 species in the south-west and one in the east, and as you've seen the flowers are colourful, big and produced singly (although often in clusters on the plant). The fourth genus, Baxteria, has only a single species, from the south-west. It too has single flowers but fairly non-descript. This is Calectasia grandiflora in the Stirling Range.

Apart from that one species of the tinsel lily genus, Calectasia, all Dasypogonaceae are from the far south-west corner of Australia. Otherwise it's hard to find much they have in common. In the most recent classification based on molecular sequencing, the so-called APGIII (2009), the authors were still unclear about what to include in the Dasypogonaceae, and this remains the case today (2015).

Eventually, these genera might be combined with another order once the relationships are clearer (i.e. what is its nearest relative). But for now it's a convenient little dumping ground for plants mostly only found in the south-west and including these two distinctive genera.

What we can say is that Calectasia and Kingia have a common ancestor shared with a few other south-west Western Australian endemics and can be considered close relatives in an evolutionary sense. Otherwise, though, they still don't much look the same.


Sue Catmint said…
so interesting, Tim. How do botanists work out the common ancestry of these extremely disparate looking plants? Is it by gene sequencing? I've never been to the south west, and am dying to go, seems it is a unique ecosystem.
Talking Plants said…
Yes, these days with genetic sequencing, backed up by re-checking more traditional characters and often finding things we missed or misinterpreted. A fascinating part of the world floristically! Tim