In my world, there is an organism much like grass except for four things: it can think, it colonizes every surface on its home world, it has the option to perform chemosynthesis, and its parts can transfer information between its members.

Essential Question: What type of traits different from that of common grass would be necessary to achieve this?

  • $\begingroup$ If it colonizes every surface on its home world, does it colonize surfaces on itself (blade of grass growing from blade of grass growing from...)? $\endgroup$
    – Frostfyre
    Mar 2, 2016 at 17:19
  • $\begingroup$ also, how does it handle oceans? does it spread over the surface or the sea floor? if not, how does it get to and communicate with other continents? $\endgroup$ Mar 2, 2016 at 17:45
  • $\begingroup$ @Frostfyre no , no it does not $\endgroup$
    – user15036
    Mar 2, 2016 at 18:23

3 Answers 3


Getting a large single organism

The largest living terrestrial organism is the Aspen.

Each "tree" is actually genetically identical piece of the organism connected by root structure to each other. Aspen groves can be 5 miles or more on a side.

That said, I would say that a grass using some sort of root/vegatative propagation (aka Rhizomes) are the essential feature of plants covering a large area with a single organism.

Rhizomes provide the plant with the ability to cover vast areas with a single organism but provide no benefit to the plant developing intelligence or the ability to colonize.

Getting intelligence

Intelligence requires a lot of energy. The human brain composes just 2% of the human body mass but consumes 20% of the human bodys energy production. It is thought that intelligence's high demand for energy may require that organisms with high intelligence must consume other organisms high in protein and fat to supply enough energy.

Unfortunately, plants are even more energy poor than herbivores. Based upon the information in one of my prior answers (How much land area do ... herbivores need for food?), it takes at a minimum 1 acre of plant life to supply enough energy to keep 1 human fed. Presumably this 1 acre of energy production would be enough to keep the plants alive in the area but not enough for vigorous growth, competing with other plants, or intelligence.

Presumably your world girdling grass would require more land than this to harvest the energy it needed for both growth and intelligence. When the plant covered smaller areas, its intelligence would (based upon energy needs) be less. It would struggle competing with nearby plants that used all of their energy for growth.

As the plant grew in size, its intelligence could go up. I would guess that for human level of intelligence you'd need many acres of land (5+?) to develop consciousness.

Maintaining a single consciousness across distances

I don't know of any plant mechanisms for transmitting signals, other than chemical signalling. If this is the only method of signal transmission, then plant thought will be substantially slower than human thought - especially when considering the distance traveled.

I know of no method of transmission across uninhabitable portions of the planet (deserts, oceans, & mountains). You might end up with plant entities taking up entire continents. On Earth this might be 5 plant entities covering the continents (North America, South + Central America, Eurasia, Australia, and Africa).

  • $\begingroup$ In my opinion this is all great. My feedback is that it brings up more problems than offering solutions. Can I suggest that we answer how a plant would achieve more efficient harvesting of energy so that intelligence is possible? Maybe an atmosphere that absorbs less solar energy before it reaches the ground? Geothermal roots? Highly fertile soil? $\endgroup$
    – Muuski
    Mar 2, 2016 at 19:16
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    $\begingroup$ @Muuski, it is the nature of renewable energy such as solar to be very diffuse. Animals eating those plants concentrate the energy. When we eat the animals we are getting it concentrated again. A higher energy environment would still mean animals have more energy to burn than plants. Remember organisms use energy flow to store energy, so you need both energy source and sink. $\endgroup$
    – Jim2B
    Mar 2, 2016 at 19:48
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    $\begingroup$ I don't understand what you mean by "concentrate the energy". Does this mean that if a plant had access to enough energy and stored it in a cell similar to animal fat, the concept would suddenly work? $\endgroup$
    – Muuski
    Mar 4, 2016 at 13:05
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    $\begingroup$ A cow harvests plant energy over both energy and time. When a human kills and eats a cow, they get the advantage of all the effort used by the cow to collect that energy. Harvesting is relatively inefficient but by doing this it means the human doesn't waste time, effort, and energy having to do it. It also means the plant loses the energy, time, and effort investment. $\endgroup$
    – Jim2B
    Mar 5, 2016 at 2:34

You want a creeper for this rather than grass. Japanese Knotweed a favourite but you could also consider something like Ivy.

Fast growing, able to grow up any surface regardless of angle, perennial, almost impossible to kill and a single plant can cover a vast area.


I think you've pretty much covered it:

1) it can think - Grass can't think.

2)it colonizes every surface on its home world - Grass only grows in sunny, non-desert, non-polar conditions.

3) it has the option to perform chemosynthesis - Grass can't do that.

4) its parts can transfer information between its members. - Grass can't transfer information.