Plant of the week #4

Cassytha pubescens
(Downy Snotty-Gobble) 

A brief description: Also known as dodder-laurel, devil's twine, jungle string or love vine, this interesting plant is actually a parasite. All species in the genus are hemiparasites, meaning they still photosynthesise and tap into the host plant's xylem (taking water and the associated dissolved nutrients) but not sugars. It is rootless as an adult (although the seedlings have roots) and is completely dependent on its host for survival. Flowering and fruiting in summer, the picture above shows some flowers in bud and opening, as well as some immature fruit. The host in this case is an Acacia pycnantha, although it is a generalist parasite and will grow on pretty much anything (even barbed-wire fences!).


Taxonomy: The taxonomy of this genus is not well researched. There are approximately 23 species, 16 of which are endemic to Australia. The genus is placed within Lauraceae, often within it's own subfamily as it's so weird. *It is unrelated to the Dodder species in the Cuscuta genus. They're a completely different family (Convolvulaceae) and are an excellent example of convergent evolution as they look very similar but are completely unrelated, and physiologically very different*

 Distribution: Eastern states; Coastal SA, Vic, Tas, NSW and QLD. Also found in New Zealand and Japan (introduced).

Conservation status: Locally common, not considered at risk in the wild. Distribution is typically patchy


Interesting things about downy snotty-gobble: There are many, where should I start?! (this is the plant I'm studying for my PhD, so I'm perhaps a bit biased :P). It has been seen to damage some weedy species in South Australia, even killing Gorse (Ulex europaeus) and Scotch Broom (Cytisus scoparius) but not the native species. This is thought to be due to the native species co-evolving with Snotty-Gobble.
The other thing I find rather interesting, is the seedling stages of this parasite. It germinates and grows for the first 6-8 weeks with a short root (usually no more than a couple of cm long) which dies back after it's found a host and wrapped itself securely around it. This means if there's a disturbance such as a fire, the adults are all toasted and it's up to the seeds left in the soil to re-establish the population. Interesting, yes?