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Lithops project blog


This is the blog page of the Lithops Project, in which we investigate the extent and evolution of locally optimized camouflage coloration in the enigmatic African "stone plants" belonging the genus Lithops.

In the first part of the project, we use hyperspectral and multispectral camera equipment for making detailed comparisons of the visual properties of Lithops species and the soil on which they grow across numerous locations in southern Africa.

We set out for our second month-long field expedition on June 27, 2018. As on the 2016 expedition, we aim to post updates every 2-3 days.

Our imaging expeditions are supported by National Geographic Society Science and Exploration Europe. Hyperspectral camera equipment is provided by Specim Spectral Imaging Ltd. and the Surface Optics Corporation.

For more information on our project, check out

Drought problems

Expedition blog 2016 Posted on Wed, April 20, 2016 11:44PM

We decided to stop in Springbok for the night, mainly for having our second shower of the expedition. We got one Lithops marmorata population processed in the morning, despite challenging light conditions – both of our camera systems require long exposure times, so windy and half cloudy is almost the worst possible weather for us. The search at the next site failed miserably, but we saw a lot of other interesting plants!

Our difficulties with finding good Lithops populations in northern Namaqualand are partly caused by low rainfall in the last months, which means that the autumn is late and the plants have not yet started flowering. In addition, the plants that we do find are often crumpled (like the Lithops marmorata below), and we also find the dry remains of dead Lithops plants. Although Lithops are decidedly adapted to dry conditions, at many sites they seem to be at their limit at the moment.

Lithops pictures

Expedition blog 2016 Posted on Tue, April 19, 2016 07:29PM

Since this is officially a blog on Lithops, I’ll also post Jeroen’s informative schematic illustration of the structure of Lithops plants, and a photo of the cute species Lithops olivacea.

Our photographic arsenal

Expedition blog 2016 Posted on Tue, April 19, 2016 06:40PM

We’ve been in the backcountry for a few days, but now we’re camping near the N7 highway with a cellphone tower in sight. We’ve gotten our routines running, and have managed to process two populations on the best days. Today our luck was worse – our work at the first Lithops marmorata site in the morning was cut short by rain, and in the afternoon a thunderstorm developed right when we were imaging another population.

Below are a couple of pics of our photographic arsenal. At each location we aim to measure 10-20 individual Lithops plants and the soil on which they grow. To get a detailed view of the spectral properties of the plants, we use a Surface Optics SOC710-VP hyperspectral imager. The hyperspec camera records reflectances at 128 wavelenght bands between c. 400 and 1000 nm. Note that there is actually a Lithops plant right below the camera in this photo.

The same individual plants are also photographed using a Nikon D7100 DSLR camera that has been modified so that it records both visible and ultraviolet (UV) light. In this case, we take two images, one using a UV-blocking filter (so that we get standard visible-light RGB images) and one using a filter that blocks visible light (so that we get a UV picture using two of the sensors). The filters are changed between the shots using a slider rig that is a variant of Jolyon Troscianko’s model (see The slider and the two filters are visible in front of the lens in the photo below.

The white ecosystems

Expedition blog 2016 Posted on Thu, April 14, 2016 09:54PM

After another couple of days in the field, we decided to stop in a guesthouse in Kenhardt for the night, for the following reasons: charging camera and laptop batteries, backing up tons of image files, and showering. The last reason was the most important, because Allan, Willem, Jeroen, and Matt started to reek seriously (I still smell like flowers).

In the last days, we’ve gotten into whitish quartzite soils, in which many animals and plants are very pale, forming whole white ecosystems.

Avonia sp.:

The alien-looking Dinteranthus pole-evansii, which looks like a cracked golfball:

Then an again gigantic, but white, Trachypetrella stone grasshopper (we’re starting to suspect that some of these are new species):

And a cute little wingless Ligariella praying mantis:

And, somewhat unsurprisingly, the minute Lithops fulleri has white flowers:

The other weirdoes

Expedition blog 2016 Posted on Tue, April 12, 2016 05:33PM

Lithops species are not the only plants that look strange in South African deserts, also other groups use camouflage for avoiding detection. Here’s a Titanopsis species.

The grazing pressure on sheep and cattle pastures is high in many places, but many plants manage to avoid being eaten by growing flat on the ground.

And the insects are no less strange or well-camouflaged, Willem found this enormous toadhopper today when it happened to move a bit, the monster was about 12 cm long!

Small successes:)

Expedition blog 2016 Posted on Tue, April 12, 2016 05:10PM

Yesterday started badly, we spent most of the day driving and checking localities reported in Desmond Cole’s classic Lithops book, but found nothing. In the afternoon, we changed strategy and started asking around farms for Lithops
sightings, and got a hint that eventually led us to a 85-year old farm
worker, who gave us good instructions. Unfortunately we had to set up
camp before getting to the place, because it was getting late.

But in the morning the information proved to be correct! We found a good-sized population of L. hookeri,
and spent most of the day doing multi- and hyperspectral imaging of the
plants. Now we are having a short break in Prieska, but soon we’ll head for new adventures.

The hyperspec camera is finally here

Expedition blog 2016 Posted on Sun, April 10, 2016 02:27PM

Hero of the day: Matt Britton (on the left below) drove all day
yesterday to bring us the hyperspec camera once it had been released by
the customs! He arrived late, but made it in time to see our first
proper UV results.

We’ve been living on the porch of a farmhouse some way from Hopetown for the last couple of days, but now we’re again
headed for more remote regions.


Expedition blog 2016 Posted on Sat, April 09, 2016 05:33PM

The sun is finally here again, after days of rain and wind. This definitely more like what I expected. Yesterday we did a lot of prospecting in new spots, but with no luck with regards to Lithops. The scenery is amazing though.

Today, we have perfected our VIS+UV photography skills at two previously-known locations. Lithops hookeri is flowering beatifully at this time of the year, which makes finding them a lot easier.

Note that Willem also posts images on Instagram, those can be found at !

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