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.

Leaf Features

It has opposite, papillose, succulent leaves that are lanceolate with entire margins.

Flower Structure

Its solitary flowers have five white tepals that are yellowish green on the outside, 5 to 15 stamens, and an ovary with 5 locules.

Fruit and Seeds

This structure develops into a pentagonal fruit capsule that holds 2 brown seeds in each locule.

Dispersal Mechanism

This species has an unusual seed dispersal mechanism. When it rains, the locules gradually fill with water.

Nozzle Structure

Near the center of the capsule, covering membranes are arranged to form a nozzle.

Dispersal Process

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.

Native Range

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.

Additional Distribution

It also grows in the Mediterranean region and the Canary Islands.

Germination Study Baseline

Laboratory studies have found that Aizoanthemopsis hispanica seeds germinate poorly when placed on filter paper in the dark at 30 °C (86 °F).

Germination Improvement Methods

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.

Germination Stimulant Hypothesis

This suggests that both soil and covered seeds release some gas, possibly ethylene, that stimulates germination in nearby uncovered seeds.