Lithops dorotheae

The series on mimicry and deception written by Taisha continues. She scribes:

This is an image of Lithops dorotheae, submitted via the Botany Photo of the Day Flickr Pool. The photo is courtesy of Van Swearingen (aka Van in LA@Flickr). Thanks Van!

Members of the genus Lithops are known as the living stones. Most of the genus is found in arid areas of southern Africa, with Lithops dorotheae occurring near Pofadder, an area in the Northern Cape of South Africa. Lithops dorothea grows among fine-grained sheared quartz feldspar and feldspathic quartzite. Species of Lithops mimic the stones of their natural habitat in order to avoid herbivores. In the case of Lithops dorothea, the foliage is therefore reddish- or yellowish-brown, with some white to match the feldspar and quartzite. Camouflaging to reduce the rate of detection by antagonists is termed crypsis (Daniel: see some quoted material on crypsis below in the comments).

Morphologically, plants of Lithops (link contains illustration) are composed of a root and the plant body (aka corpusculum or head). The body is made up of two opposite leaves that are thickened and fused together, with a fissure down the middle. On the aboveground surface of the leaves, transparent or translucent windows permit light to penetrate deeply into the photosynthesizing parenchyma tissue of these CAM plants. The exposed area of the two leaves is collectively referred to as the face, and many variations exist amongst the genus in shape, texture and colour. The remainder of the conical plant body resides underground, presumably as an additional means of avoiding herbivores as well as protecting the plant from dessication.

Lithops are perennial species which undergo an annual cycle of growth, flowering and decline. Each year, a flower bud will develop below ground then break through the cleft of the two leaves to bloom. The seeds produced are in an specialized capsule that lacks a covering membrane. The capsule is closed to protect the seed during arid conditions, but will open during a rainfall to release the seeds. After flowering, the plant undergoes a dormant period where the body shrivels. Growth of a new body is eventually initiated, with nutrients extracted from the old body. The dried body of the old plant surrounds the new growth. After some rainfall, the new body will burst through the remainder of the old one, with the new pair of leaves’ fissure 90 degrees from the previous pair.

Lithops dorotheae

8 responses to “Lithops dorotheae”

  1. Daniel Mosquin

    On crypsis in plants, from Schaefer and Ruxton’s excellent Plant-Animal Communication (2011):
    “…putative examples of crypsis are few, and experimental explorations of plant crypsis are absent. Although we know of no study that has demonstrated this, it is difficult to imagine any explanation for the extraordinary likeness of South African Mesembryanthemaceae plants such as Lithops species to stones other than to provide protection via crypsis.”
    As an aside, Lithops are placed in Aizoaceae within the APG III system.

  2. Linda

    I used to grow lithops in pots which I loved to leave around the house for unsuspecting visitors. Why do you have pots of rocks around? Lithops come in fabulous colours and patterns. It was a moment of pride when they split to reveal the new ‘leaves’. I am really enjoying this series on plant mimicry.

  3. awanderingbotanist.com

    I too love Lithops, tho I have never personally grown them.
    Is this photo from nature? Are there natural conditions under which they are that densely packed?

  4. Wendy Cutler

    I can only answer the first part of the question. From the tags with the original photo and the others posted with it, it seems it was taken at Huntington Desert Garden, part of The Huntington Library, Art Collections and Botanical Gardens in San Marino, CA. According to Wikipedia, that garden has the largest collection of lithops in America.
    Thanks for this very interesting series.

  5. Denis Dooley

    I have a soft spot for these to the point that I have “rescued” them from Walgreens, where they were surely doomed to a quick death by overwatering.

  6. DrBob

    There is a grass genus Crypsis, the prickle grasses. The genus name comes from the Greek word for concealment. The inflorescences of several species stay tucked within inflated leaf sheaths. Several of these weedy Eurasian annuals have become established in North America, where they are important rice field weeds and, here in California, compete with endangered vernal pool plants.

  7. Diane Wilen

    Does anybody know if they’ll grow in Colorado at about 7,000 ft elevation?

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