About Aizoanthemopsis hispanica (L.) Klak
Aizoanthemopsis hispanica (L.) Klak is a sprawling annual herbaceous plant that reaches 5 to 20 cm (2 to 8 in) in height. It has opposite, papillose, succulent leaves that are lanceolate with entire margins. Its solitary flowers have five white tepals that are yellowish green on the outside, 5 to 15 stamens, and an ovary with 5 locules. This structure develops into a pentagonal fruit capsule that holds 2 brown seeds in each locule.
This species has an unusual seed dispersal mechanism. When it rains, the locules gradually fill with water. Near the center of the capsule, covering membranes are arranged to form a nozzle. When additional raindrops strike the capsule, a jet of water carrying seeds is propelled out through this nozzle, which lets the plant scatter its seeds much more widely than related species that do not have this mechanism.
Aizoanthemopsis hispanica is native to Egypt, Israel, Jordan, Syria, Cyprus, Turkey, Iraq, Iran, and the Arabian Peninsula, where it grows in compacted sandy soil in desert plains, saline areas, and semi-arid regions. It also grows in the Mediterranean region and the Canary Islands.
Laboratory studies have found that Aizoanthemopsis hispanica seeds germinate poorly when placed on filter paper in the dark at 30 °C (86 °F). Germination rate can be improved by placing soil near the seeds, covering the seeds for a few days then uncovering them, or placing covered seeds near the target seeds. This suggests that both soil and covered seeds release some gas, possibly ethylene, that stimulates germination in nearby uncovered seeds.
