Few plants survive in a desert because the climate is too dry.
Because there isn't enough water or moisture in the soil for plants to take up through their roots so normal plants can't survive in the desert.
Because not all of them find conditions that are suitable for germination. After germination a number will die or be eaten by pests, killed or damaged mechanically, die because of drought, frost etc. The more seeds the greater chance for the survival of a few plants.
Not many plants grow under casuarinas because of the needles. Plants dont have to grow everywhere, Apart from human cleared areas casuarina needles create some of the few gaps in the forest for animals to hang out in. I could tell you which species grow naturally under them in my area. But they may not be endemic to your area. There are a number of invasive weeds that are able to grow under Casuarinas. These are terrible plants and I certainly dont want people to grow them. Ehrharta erecta, Cyperus, Bidens pilosa. Plants can grow from runners or suckers in Casuarina needles also. An example of a tree that can grow by suckering through Casuarina needles is the Casuarina. =] . Go out and see what grows under them naturally in your area, and if you are going to grow some yourself insure that they are provenant to your area. read - What is provenant? I only propagate endemic provenant indigenous plants. I dislike people who treat plants like toys. "OW Look isn't that JESSAMINE pretty , I'm going to plant it everywhere because I'm an *&^%$#@". Know what I mean?
Plants need quite a few things to grow, it needs sun, carbon dioxide and water to make food, the food is glucose this process is called photosynthesis. The "Vacuole" (a particular part of the plant), stores all the food. Water is also needed every so often, some plants for example a cactus, can store water inside it's body for up to a few years maybe, but other plants would need water every day.
Non-vascular plants, such as mosses and liverworts, can vary in size from very small, like tiny liverwort thalli measuring just a few millimeters, to larger mosses that can grow up to several inches or even a few feet in height. Generally, non-vascular plants are smaller and more compact compared to vascular plants because they lack the specialized tissues for water and nutrient transport.
To successfully grow pineapple plants from pineapple seeds, follow these steps: Obtain fresh pineapple seeds from a ripe fruit. Remove the seeds from the fruit and let them dry for a few days. Plant the seeds in well-draining soil and keep them moist. Place the pot in a warm, sunny location. Water the plant regularly and fertilize it every few months. It may take 2-3 years for the plant to produce fruit.
There is no or little farming in much or north Africa along with southern Africa because of the climate. It's getting farther away from the equator and the climate starts to get colder.
Few plants grow tall on the forest floor because there is a lack of sunlight.
There are few plants and animals hardy enough to survive in the Sahara’s arid climate.
dessert
There are a few plants that grow better with morning sunlight. Some of the plants are spring bloomers, pansy and sunflowers.
There can be more plants. But very few people know it.
The venus fly trap grows in a small region in North and South Carolina. There are few plants left in the wild, and are considered threatened.
A desert
There are quite a few plants that grow in low moisture climates. These plants will typically have very thick protective tissues.
There are quite a few plants that are fun to grow. Marigolds, nasturtiums, peas, beansprouts, and mustard are all easy and fun to grow from seeds. You can even grow a plant from a carrot top.
Sandy soils have little moisture and few nutrients. Therefore, most plants can't grow well. Adapted plants such as cactus have evolved to grow in sandy soil.
There are very few plants that grow on Mount Whitney. The types that are seen the most there are Sky Pilot plants.