The Atmosphere Plant

One short phrase links:

Edgar Rice Burroughs' Mars;
SM Stirling's Mars;
several extrasolar planets described by Poul Anderson.

I have commented on this blog that Anderson often describes the equivalent of grass on habitable planets. Stirling does the same for his Mars:

"'...the atmosphere plant'...That low-growing, waxy-leaved plant was the Martian equivalent of grass..."
-SM Stirling, In The Courts Of The Crimson Kings (New York, 2008), p. 63.

However, it is more:

"...and also, ecologically, of oceanic plankton; it kept the oxygen content of the air. It had a fantastically efficient version of photosynthesis, flourished nearly everywhere, and stood at the bottom of nearly every food chain. An area too hostile for it was likely to be bleak indeed, even by this dying planet's standards." (ibid.)

Maintaining the oxygen supply, this plant must have been designed by the terraformers of Mars. Also, the current inhabitants use organic technology so maybe they too are partly responsible for the atmosphere plant's fantastic photosynthesis.

ERB's Mars, Barsoom, would already be dead if the red Martians did not artificially maintain its atmosphere with a factory called - the atmosphere plant!