The genus Lithops, commonly known as “living stones,” consists of remarkable succulents native to the arid landscapes of Southern Africa. These plants store water in their two fused leaves and mimic the surrounding pebbles for camouflage. Understanding how these organisms reproduce begins with a close look at their seeds, which are surprisingly complex despite their minute size. This exploration details the structure that protects them, their physical characteristics, and the techniques needed to handle this delicate material.
The Protective Seed Capsule
The seeds of Lithops are housed within a specialized fruit called a capsule, which develops after the flower has been pollinated. This capsule is a small, dry structure typically containing between four and eight internal chambers where the seeds mature. The structure is highly adapted to the plant’s dry native environment.
The capsule possesses a hydrochastic mechanism, meaning it only opens when it contacts moisture, such as rainfall. When wet, the outer layers swell and peel back, exposing the seeds within the chambers. This ensures that the seeds are dispersed only when environmental conditions are suitable for immediate germination and seedling survival. Rainwater splashing onto the open capsule helps eject the seeds up to a few feet from the parent plant.
Describing the Seeds’ Appearance
The physical characteristics of an individual Lithops seed are distinct, though they are difficult to observe without magnification. They are often compared to fine dust or grains of sand, typically measuring between 0.3 and 1.5 millimeters in length. Thousands of seeds can be contained within a single small seed capsule.
The color generally ranges from dark brown to black, sometimes exhibiting reddish-brown tones depending on the species. The most common shape is kidney-shaped or crescent-like, but some species produce seeds that are spherical, oval, or triangular.
Seed surfaces vary significantly among different Lithops species. Textures are classified as smooth, rugose (wrinkled), or tuberculate (bumpy or warty). These microscopic differences in shape and texture are features used by botanists to distinguish between species within the genus. The dark coloration and tiny dimensions require careful handling during collection and preparation.
Preparation and Sowing
Collecting the seeds often involves wetting the dried capsule to trigger the natural dispersal mechanism, releasing the seeds for storage or immediate planting. Successful propagation requires a specific method of handling due to their minute size. They must be surface-sown, meaning they are simply scattered over the top of the planting medium and are not covered with soil.
Burying the seeds, even slightly, prevents germination because they require light to initiate the sprouting process. After sowing, the seeds need a consistently high level of moisture and humidity to break dormancy and begin growth. This is often achieved by enclosing the container or using a method like bottom-watering, which keeps the surface moist without displacing the delicate seeds. Controlling humidity ensures the tiny seedlings have the necessary environment to develop after emerging from the seed coat.