Plants that grow in extreme environments, such as the desert have a number of adaptations which enable them to survive:
Reduced leaf areas - in some cases spines have replaced leaves, this not only affords protection from predators, but reduces transpirational water loss.
Thick waxy cuticles - reduce water loss and prevent dehydration.
Water storage organs - many have developed thick layers of tissues to absorb and store any excess water (when there), some have storage organs below ground where they can store surplus water.
Light or silver coloured leaves - these help reflect direct sunlight and keep the plant cool.
Minimal amount of stomata - they have fewer stomata than other plants, this reduces the amount of water lost by transpiration.
Shallow root systems and deep root systems - some desert dwellers have shallow root systems to capture and absorb even the most minimal amounts of rain that may fall. Others have extremely deep root systems which may penetrate tens of meters into the soil in search of water stored below ground.
Slower metabolism - at extremes in temperature most plants enter a low metabolic state - this slows the plant down so that it uses less resources, energy and water
Wet soil and mildly hot tempatures
Cacti, pineapples, agaves, and geraniums are some plants that are adapted to hot, dry conditions. They would all survive well in the desert.
yes
The reaction of photosynthesis needs energy, so cold weather does not help plants to create food. In extremely hot weather the plant's enzymes are denatured so they lose their shape making them useless. Neither extremely hot nor extremely cold weather are good for the plants.
The plants that grow in hot and dry conditions are called xerophytic plants. Water conservation is key to their survival. So, they have innovated a new protocol of photosynthesis called CAM pathway, i.e., Crassulacean acid metabolism. In this pathway, such plants keep their stomata open in night to take up CO2 while their stomata remain closed during the day in order to avoid transpiration. In the daytime, they synthesize glucose from CO2.
Dry, hot, desert like conditions.
By adapting themselves to such conditions.
in Avery dry and hot conditions with vegetation (trees and plants)
well it helps the trees grow
Earth would not have any extremely hot/cold weather conditions.
extremely hot
There are several areas where the climate features extremely cold winters with a lot of precipitation and hot humid summers. Cities in a midlatitude desert experience these conditions.