On trees this could look awesome if leaves get a own tile. The algorithm should be very similiar to the algorithm that generates waves on the ocean.
Grasses actually can get a pretty decent size, some get over 1.80 Meters (f.e: Calamagrostis acutiflora). Bamboo is actually a grass. Lets dont forget stuff like Giant Hogweed which actually pretty dangerous.
The size of plants could be actually be part of the description for plants if plantgathering gets more detailed - maybe as part of some kind of encyclopaedia like this:
This is giant Hogweed (Mundane).
Giant Hogweed is a phototoxic plant. Its sap can cause phytophotodermatitis (severe skin inflammations) when the skin is exposed to sunlight or to UV-rays. Initially the skin colours red and starts itching. Then blisters form as in burns within 48 hours. They form black or purplish scars that can last several years. Hospitalisation may be necessary.
Giant Hogweed may reach 2-5 metres (rarely to 7 m) tall. a stout, dark reddish-purple stem and spotted leaf stalks that are hollow and produce sturdy bristles. Stems vary from 3-8 cm in diameter, occasionally up to 10 cm. The stem shows a purplish-red pigmentation with raised nodules. [....]
Especally as soon we get to stock fantasy and procedural generated plants a little herbalistic ececlopedia might be usefull - as well as books for herbalists.
Would it possible to give wounds and rotting/infected tissue the chance to emit Miasma in small amounts? The smell in hospitals etc. wasnt. that likeable in the medieval times.
Ok back To something different:
Mostly because there's no reference to Montesquieu's tripartite system, almost everything is under the noble's rule, though right now the king got less power then the mayor 
OK this only a theory but maybe King is only some official title and Mayors, dukes etc. are part of a mix from a "
elective monarchy" like in the old "Holy Roman Empire of German Nation" and a "representative Monarchy". Dukes (all along with other rights like setting taxes, mining rights etc.) might have the right to elect (and remove) a king/ royal bloodline from their group. The King at himself doesnt need that much additional rights if Kingship among dwarfs is more a representative thing.
This could mean the king Represents the dwarven civ to the other civs in negotiations, is the highest military officer and Ruler (aka. Mayor) of the capitol with or without own Land. He also could be some Kind of more or less neutral Judge in twists between 2 or more dukes.