Note: This question is a follow up to this question, and hence forms part of a bigger complex of questions about geology and biology in this certain scenario.
Meta: The planet consists of two enormous continents, each encompassing one of the two hemispheres (northern and southern). There are two small polar oceans (both mostly frozen over, encompassed by landmasses) that are relatively low in salt. The continents are divided by a huge, deep oceanic belt, along the equator of the planet.
The planet has bout 1.1 times the mass of Earth, and slightly more landmass than water (about 35% percent landmass to 65% waters).
Tectonics push plates from the equator to the poles, effectively forming mountain rings, parallel to the equator, on the continents.
The planet orbits at an Earth-like distance around and Sol-like sun with an Earth-like elliptical orbit.
The planet will have 3 satellites (aka. moons), the first is sized a trifle bigger than Earth's moon and is orbiting along the equatorial axis about the same distance as earth's moon, and the others are both about 1/3rd the size of the big moon and are at a 60° and 70° degree inclination relative to the plane of the biggest moon at less distance from the planet.
The planet will feature a Phlebotinum gas, providing about 400-500% the lifting capacity of helium/hydrogen (as described here).
Regarding the stated facts, How would flora develop and behave on such a planet?.
To mention a few topics:
- How many species of a given plant (e.g. trees, wheat, grasses) would evolve?
- Would there evolve different species per climate zone or would the same species rather evolve specializations?
- How different could the flora on the northern hemisphere be from that of the southern?
Addendum: This question assumes no travel of people between both continents, nor does it assume any cultivation of plants, no plantations made by humans. Best assume NO humans at all for the sake of the question.