Plants thriving in deserts or adapted for living in arid regions are called xerophytes. The word is derived from the Greek words xeros meaning dry and philein meaning to love.
Some of xerophytes are also succulents if they store moisture in thickened leaves, stems or underground parts. The Echeveria leaf rosette in picture, an exotic commonly seen in South African gardens, is a robust leaf succulent.
The stored resources serve to keep the plant alive in stressful dry seasons or years and to allow them to produce flowers and set seed in season. The word succulent is derived from the Latin word succus meaning juice.
Halophytes or plants living in saline and mangrove swamps, semi-deserts and seashores sometimes overlap with the grouping of succulents. Examples include the Sarcocornia genus, often spotted close to the sea along many parts of the South African coast.
Wherever these plants may come from, they are often astonishingly beautiful. Although succulent plants are often thought of as robust and hardy, they are, like everything else in nature, adapted to live in conditions subject to limits before coming under threat.
These risks include exceeding intervals of temperature, levels of moisture and nutrients and the absence of certain chemicals from the air, water or soil they live in.
Additional manmade risk dimensions to serve the needs of escalating human numbers come from economic growth. This translates into urban sprawl, larger scale farming including vast monoculture planting, infrastructure development including the devastation of natural vegetation and the introduction of non-indigenous plant species into new areas in many places.
As major environmental changes always spill into new unintended and unforeseen areas, water and air pollution and the introduction of numerous chemicals, including herbicides and insecticides change the fortunes of plants and animals on earth across the living range.
The scientific and technological brilliance that drive our never-ending list of new human comforts, may in future also be directed at balancing development on earth for saving species and limiting human impact. The halfhearted response to the growing negative trend is so far not promising.
The unspoken argument from nature arrives in disruption on an unknown scale of escalation. We can measure parts of it as funding of the sciences allows and excite the population from time to time by reporting sensational events in the media. The trick will be to respond effectively before the impact precludes significant counteraction (Van Jaarsveld, et al, 2006).