Plants are a lot more complicated than evolutionists are willing to admit. We can hardly chalk up their growth to Darwinian processes.
A paper published in Nature Plants discusses the molecular machinery that builds plant cell wall components.
Phys.org gives the gist of what goes on in plant cells:
“Two proteins embedded on membranes within plant cells serve as a scaffold to organize three key enzymes that specifically channel carbon into the synthesis of a cell-wall polymer called lignin.
Lignin is essential to plants' ability to grow upright and represents a substantial carbon-storage component of plants. But because it surrounds the other cell-wall components—cellulose and hemicellulose—lignin protects these carbon-rich substances from the biochemical processes commonly used to convert them to fuels or other bio-products.”
Building a plant gets quite complicated. While the three enzymes “are located near one another on a membrane known as the endoplasmic reticulum, they don't interact directly. Instead, two separate proteins interact with all three enzymes."
The endoplasmic reticulum is the “cell's interior ‘highway’ of membranes lined with the molecular machines that make proteins and transport those products within or out of cells.”
It should not be too difficult to see evidence of an intelligently designed system in all this. Molecular protein-making machines do not come about through trial and error. Designing them requires intelligence, as does the transportation business they’re involved in.