In that case, that is more a general description of what the Domain provides and the flavor it's going for rather than an actual power.
EX "Can grow defensive thorns" is the Wooden Fist and Bramble Armor abilities (note both mention thorns), and "communicating with plants" refers to the various Domain spells that manipulate plant life (Entangle, Plant Growth, Command Plants, Animate Plants, and Control Plants).
It's fluff text, in other words. It confers no additional abilities.
Except Travel domain, in the same section, gives 10 feet to base speed.
That doesn't sound like fluff.
That one isn't, because it gives a mechanical benefit. Domains are a bit inconsistent.
On the one hand, you have ones like the Travel Domain, which gives +10 speed in that section, or the Trickery Domain, which grants Bluff, Disguise, and Stealth as class skills.
These ones have specific, clearly spelled out mechanical benefits listed.
On the other hand, you have Domains like the Void Domain, which says "You can call upon the cold darkness between the stars to gain flight, travel to other worlds, or summon monsters from beyond to do your bidding." which clearly refer to the abilities actually granted (Overland Flight, Interplanetary Teleport, and Planar Binding as Domain spells being "flight", "travel to other worlds", and "summon monsters from the beyond" respectively).
It's pretty easy to parse out which ones are which.
On a third hand, you have ones like the Law Domain ("You follow a strict and ordered code of laws, and in so doing, achieve enlightenment.") or War Domain ("You are a crusader for your god, always ready and willing to fight to defend your faith.") that do neither.
Domains are all over the place.