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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

Back in Cape Town

Expedition blog 2016 Posted on Sun, May 01, 2016 10:40PM

Sadly, the Lithops 2016 expedition is now officially over. Awesome trip! The following months will be used to analyze the massive image dataset that we collected during the expedition.

We arrived in Cape Town in the afternoon, and have spent the evening unpacking and cleaning gear, showering, and eating. More posts will follow later, after sleeping and sorting out our photo files.

First rain day

Expedition blog 2016 Posted on Fri, April 29, 2016 02:57PM

Can’t really complain about the weather in South Africa: after three weeks of field work, we have the first real rain day. Because of the drizzle, we can’t photograph Lithops populations today, so we stopped for for lunch and coffee at the Kerksaal in Bitterfontein. At the same time, we’re backing up all of our image data.

Despite the rain, we have a couple of Lithops divergens sites mapped and ready for tomorrow, which will be the last full field day or our expedition.

Cold nights, hot days

Expedition blog 2016 Posted on Wed, April 27, 2016 11:14PM

The winter is coming, and the nights start to be cold – this morning the temperature dropped below zero. However, it gets warmer immediately after sunrise, and the days are still very hot.

We’ve come back south from the vicinity of Namibia, and have spent the last days photographing species in the remote areas of Bushmanland. These include Lithops naureeniae (top) and L. otzeniana (below).


Expedition blog 2016 Posted on Sun, April 24, 2016 01:20AM

By now, our daily routines have become rather standardized. Before dark, we search a good spot for camping, and make a small fire to cook food.

In a coming book called South African Field Cooking, I will describe the results that emerge. I’m sure Allan, Willem, and Jeroen have a plan during cooking, despite the fact that my still-untrained eye perceives the process like random mixing of ingredients that happen to be found in the cooler box.

After dinner we got to bed before nine and get up at sunrise. The fire is revived for making coffee. The fire pit can also be used for warming up cold feet, as demonstrated by Jeroen below.

After breakfast we pack everything in the car and head towards the closest Lithops population!

Flat tyres II

Expedition blog 2016 Posted on Sun, April 24, 2016 12:50AM

This is what our right hind wheel looked like on the morning of the second day of our trip (April 6).

Thursday morning revealed that our left hind tyre had a big gash on its side and was letting air out. As luck was, we noticed this in time and got it promptly repaired before leaving Springbok.

The last couple of days have been productive, and we’ve been processing populations of Lithops marmorata, L. meyeri, and L. geyeri. Below is a shriveled but flowering individual of L. meyeri.

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.

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