I'm looking for a word to describe terrain which is occupied by native alien life.

On Earth, I might talk about a lush valley in need of environmental protection or verdant hills that would be perfect for vineyards. These adjectives have positive connotations of beauty and suitability for human habitation. What adjective would space colonists use to describe exo-planet terrain populated by alien life, especially plant-like life they consider repulsive or hazardous?

Infested and blighted convey disgust and danger, and would be good descriptions if alien life was invading Earth. In this case, the alien life is in its own native environment.

Teeming and crawling could describe animal-like aliens, but don't work for plant-like ones. They also share a problem with overgrown: they don't make a distinction about the life being unnatural from a human perspective.

Is there a single word that will convey this fairly complex idea? I'm fine with an obscure word used by Lovecraft or 1950's science fiction if I can avoid a multi-word phrase or neologism.

The planetary survey described barren mountains, _______ lowlands, and warm oceans teeming with alien life.

An obscure word I'm considering is xenic. I thought it was a neologism, but I discovered it can refer to a microbial culture containing unknown organisms. This is close to what I'm looking for, but not perfect. Is there a similar scientific adjective that better fits my criteria?

  • 2
    Welcome to the site! I think infested would be OK if the alien life is viewed negatively. And what's wrong with overgrown? Other options are overrun, rank, rife. By the way, it is formally required that you provide an example sentence with a single-word request on this site (hover over the tag to learn more). Commented Oct 10, 2018 at 23:03
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    Uh, if this "life" is native to the planet then it's not "alien".
    – Hot Licks
    Commented Oct 10, 2018 at 23:53
  • @HotLicks From a human perspective, any life that didn't originate on Earth is alien.
    – Ben
    Commented Oct 11, 2018 at 0:14
  • Rife would seem to be useful here. It is commonly used with respect to an abundance of unwantedness.
    – Phil Sweet
    Commented Oct 11, 2018 at 0:24
  • 1
    @Ben - Alas, that is apt to be the attitude of many humans.
    – Hot Licks
    Commented Oct 11, 2018 at 0:46

2 Answers 2


Native flora

flora - The plants of a particular region, habitat, or geological period.

'Britain's native flora' ODD

Substitute your planet's name for 'Britain'.

BTW, welcome to English Language & Usage.


If you want to include animals then

Native flora and fauna

  • "lush native flora and fauna" or even "alien flora and fauna" would work in your sentence. Commented Oct 11, 2018 at 0:18
  • This is not an adjective that could be used to describe terrain.
    – Ben
    Commented Oct 11, 2018 at 1:46
  • "...lush your-plant-name flora and fauna covered lowlands...". Substituting earth yields, "...lush earth flora and fauna covered lowlands...". Commented Oct 11, 2018 at 17:26

Perhaps fecund would work for you. Its literal meaning is just fruitful or fertile (Collins Dictionary) but, perhaps due to its relative rarity and similarity to words like fungus and fecal, it has less purely-positive connotations than its synonyms. As one online article puts it

Definition: Fruitful in offspring or vegetation.

You would never guess from the sound of it that this word actually refers to something positive. There is just something about it that feels a bit off, and, in fact, the term is a regular on many lists of most hated words. Sorry, fecund (shudders).

Lily Feinn, "11 Words That Sound Dirty, But Actually Aren't, According To Reddit", Bustle, Dec 23 2016

For an even more obscure variant, the Oxford English Dictionary includes an entry for the now-obsolete synonym fecundous, which to my ear sounds even less salubrious.

So your sentence could read

The planetary survey described barren mountains, fecund(ous) lowlands, and warm oceans teeming with alien life.

It doesn't fit neatly into your existing sentence, but you could also potentially take advantage of the varying usages of endemic to good effect. This word originally just meant native to a place, but has gained the meaning common in a place, and has come to be associated especially with disease. So calling the planet's lifeforms endemic sounds more ominous and invasive than just saying that they're native.

  • Endemic does derive from the Greek root demos (people), so I could mash it together with a Greek prefix like xeno- to produce xenodemic (with a broad interpretation of "people"). It's a shame xenobiotic already has a somewhat unrelated definition.
    – Ben
    Commented Oct 11, 2018 at 4:59

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