in its lifespan a plant may develop adapatation to a changing or inhospitable environment but evolution require more time to fix an adaptive character in a population. Three scenarios can be possible: 1) the changes in the environment is so drastic that the plant does not survive and reproduce; There is no possibility of evolution. 2) The changes are drastic and plant dies but after reproduction. If Some of the progeny can survive may be it can also adapt and reproduce. If there are new favorable genetic characters in some of the new individuals they will spread in the population through several reproductive cycles. After a period this process can generate a new species. 3) changes are not so drastic, the plant can survive and reproduce giving rise to new individuals that after generations are best adapeted to the environment.

in its lifespan a plant may develop adapatation to a changing or inhospitable environment but evolution require more time to fix an adaptive character in a population. Three scenarios can be possible: 1) the changes in the environment is so drastic that the plant does not survive and reproduce; There is no possibility of evolution. 2) The changes are drastic and plant dies but after reproduction. If Some of the progeny can survive may be it can also adapt and reproduce. If there are new favorable genetic characters in some of the new individuals they will spread in the population through several reproductive cycles. After a period this process can generate a new species. 3) changes are not so drastic, the plant can survive and reproduce giving rise to new individuals that after generations are best adapeted to the environment.

Evolution - biological evolution is a process of randomised progeny and selection. So a specimen can not evolve. But it can, in some extent, adapt to environment. Still - this adaptation would not be inheritated.

Massimo gave all detailes.

Actually... plants can, at least to some extend, adapt to the environment (as stated above) AND carry some of that information to their progeny in form of epigenetic regulation. The mechanisms aren't very well understood (as far as I know) and are quite far away from my area of interest, but I've noticed some publications recently hinting to that.

Not sure what happens in other species though...

plants adapt (evolve) over long slow periods, but depending where a plants environment is it can acclimatise (this is a rapid response to the plants envirnment) to enable it to cope for example with flooding eg mangroves.

There was an interresting publication in Nature last year on this topic. Following that article a tree may evolve genetically different branches in its canopy. So also the flowers in a tree may differ genetically from each other. Following this line of reasoning also a very old tree with much new wood on its trunk will be able to evolve more or less genetically.

The difference with animals is of course that the sexcentre in an animal is one concentrated organ, while plants have there sexual tissues distributed in their organism.

See article: http://www.nature.com/news/tree-s-leaves-genetically-different-from-its-roots-1.11156

Http://www.eurekalert.org/emb_releases/2013-05/nesc-sbs051513.php

An individual can ACCLIMATE to changing conditions during its life span. For instance biomass partioning or hydraulic archictecture can alter if conditions such as nutrient or water availabity change. A response such as this reflects the plasticity of the species/individual and can be due to the expression of different genes due to specific environmental conditions. Adaptation refers what happens to the gene frequencies in subsequent generations mostly due to migration, selection (natural or artificial) or genetic drift. However, there is evidence that the genotypes of progeny of individuals can change directly due to the conditions that the maternal parent experiences. I am mostly familiar with the fact that the inherent cold hardiness of the progeny of southern seed sources of norway spruce can increase when the maternal parent is grown in a more northern environement.due to epigenetic effects. Check out the work of Oystein Johnsen (no relation) and his colleagues.