Untitled Story
Commander Johnston strode through the clearing, taking strides long enough 
  that I had a hard time keeping up with him.
"Again, how exactly did this happen?" He had been stunned by the 
  implications, and I suppose that he had avoided hearing most of the details 
  in the earlier meeting.
"Well, we landed on Ceti Alpha V 3 years ago. At that time, our ships 
  sensors showed no signs of animal life, and an atmosphere that was hospitable 
  to human habitation. So, we started the standard colonization procedures, which 
  included building Prospect, the first and currently only town."
Johnston stopped long enough to raise an eyebrow and glance at me. "I'm 
  aware of that. I am the Commander of this expedition."
"Yes sir. Sorry." We resumed our break-neck pace through the woods 
  separating the power generation plant and its noisy machinery from the rest 
  of Prospect. "Well, it seems that they have been observing us ever since 
  that time, sir. And just as we study animals from blinds, they built their own 
  blinds to study us from."
"But how? That's what I want to know!"
I could see the outskirts of the town. Prospect had originally consisted of 
  dome tents and a few log structures, harvested from the bountiful forests. The 
  selection of a temperate zone had been largely guided by the presumption that 
  it would place us close to local building materials. The town-people, the colonists, 
  that is, had since taken it upon themselves to improve their town. The town 
  now consisted of quite a few frame houses. If it weren't for the fact that I 
  knew Earth to be 75 light-years away, I might have felt I had stepped back in 
  time to a town on the eastern seaboard in the 1800s.
"Well, as I stated before, we detected no animal life when we landed here. 
  It turns out that the natives are more closely related to plant life. That accounts 
  for their coloration, seeing as their biology is based more on photosynthesis 
  and chlorophyll-like pigments."
Johnston slowed to give me an incredulous look. "Plant life? You're trying 
  to convince me that they're simply intelligent rhododendrons? Have you looked 
  at these things? They have natural armaments that could tear a man to pieces."
"And sir, if you read the reports, they have been very cooperative with 
  our scientists, as we have been with theirs. The xenobotanists have explained 
  these things. The armaments are no more unnatural than a rose's thorns! And 
  the armor plating comes from the more rigid nature of plants' cellular walls! 
  They should be just as afraid of us because we have teeth and nails. They're 
  an older species too, and much of what you're finding disturbing is vestigial."
"So, if they're so friendly, why is that no one saw any of these things," 
  I knew he kept referring to them as things just to nark me
he was making 
  this more difficult than it had to be, "until 4 days ago? Why did they 
  hide for almost 3 years?"
I took a deep breath, as much to gather my thoughts as to help maintain the 
  kamikaze pace across town. I hoped we were going to the administration center 
  and the subspace radio that would allow me to contact Earth and continue to 
  file my reports. I knew that Earth would need them, along with the reports of 
  most of the other colonists, to balance Commander Johnston's prejudice.
"Well sir, the thirty-five hundred colonists here were chosen for their 
  social stability and scientific background, showing a distinct preference to 
  established family units. That much was in the mission briefing. Unfortunately, 
  linguistics and treaty negotiation were not included in the mission profile 
  because all of our studies showed we wouldn't need any of those skills. We're 
  still trying to establish real communication. It's going to be difficult, but 
  they have some tricks that make is easier."
"What tricks? And why is it that no one saw signs of civilization on a 
  planet with an 'old race' on it, as you just said?"
Another deep breath. I noticed we were bypassing the administration center. 
  Not good, not good
"I'll answer the second question first. The simple fact is that they are 
  intelligent without any of the trappings we identify as civilization. They operate, 
  for all intents and purposes, on fresh-air and sunshine. They're like plants 
  in that regard too. They have no need to clear land, plant food, and make fields 
  and structures that can be seen from space. There is nothing on this planet 
  naturally that can harm them. They live an idyllic life. They have no natural 
  predators, and they have adapted to most anything that can kill them in the 
  environment."
"So how civilized can they be if they don't do anything?"
How did this man become mission commander? Must have been his wife, must have 
  been
"Sir, they don't do anything recognizable as civilization by human standards, 
  but they aren't human, so our standards don't apply."
The commander grunted. He was done arguing for now, but I knew it would come 
  up again eventually. He moved on to the other question
"So, again, what tricks do they have?"
"Well, it seems that they never developed vocalizations. Our xeno people 
  are finding evidence that they're form of communication was originally based 
  on community root systems, though it has adapted recently, on evolutionary terms."
"What are you dancing around, Lieutenant?"
No choice but to charge in, I suppose
"They're mildly telepathic, sir. They seem to work mostly on imagery, 
  but they're skilled, after 3 years of observation, at using our language. They 
  also have a remarkable talent for learning. It seems to me, and to many of the 
  others, that what they do is think. And they're good at it. Probably comparable 
  in speed with our computers, but able to make the intuitive leaps of intelligence."
Was it just me or did Commander Johnston shudder at this statement?
"I don't like it. They've been watching us all this time and we never 
  knew they were there."
I realized at last that our destination was the commander's home, not the largest, 
  since it only needed to house himself and his wife. Several of the family groups 
  had four or five children and considerably larger homes. As it was evening, 
  this part of the town was a little livelier. Prospect policy was to try and 
  keep work between 6 AM and 8 PM local time, allowing for some flexibility, but 
  also better family stability.
"Not to mention that this appearance kept me in the admin center for 2 
  days," Johnston grumbled. "And then there was that fault in the power 
  plants that needed command overrides and authorizations until this morning. 
  And then more paper work. I haven't even seen
"
He called out to his wife
"Rose! Where are you?"
He started up the stairs. I just kept thinking how not ready he was to deal 
  with an interstellar contact, how foolish it was in retrospect that this man 
  was in charge of an alien world.
He had reached the top of the stairs. I followed at a more sedate pace, bracing 
  myself against the banister. I made it to the landing in time to see Rose sitting 
  in her chair, nursing the commander's son. Derek Johnston, first child of Commander 
  Thomas Johnston.
She looked past the commander at me. For a second, the image of that beautiful 
  woman wavered, leaving in her place
one of them. A Ceti Alphan. I don't 
  know her name, and I doubt I can express it here, but she has managed to let 
  us know that she was the first to be planted in the human colony. The real Rose 
  Johnston died in the medical facility five days after landing, killed by the 
  sleep pod, though we didn't know it until three days ago. Then we found out. 
  Found out that, among other things, they thrive on positive human emotions. 
  And in their scanning of our primitive minds, they understood that this death, 
  the death of the true driving force of our camp would end a lot of positive 
  feeling. We had all been feeling pretty good to have made it. And so this alien, 
  in an effort to preserve the happiness of our little camp, took Rose's place.
As I stood their watching, the alien suddenly appeared to be wearing a wedding 
  gown, and a felt a query in my mind. No, I though, shaking my head. He's not 
  ready to truly understand this relationship, though I had to laugh at how absurd 
  it looked. So the image of Rose reformed in my mind, and I watched the commander 
  kiss his wife and take his son and carry him
I guess it makes some sense. A rose by any other name
Raven's Comments:
A fun and amusing twist at the end, there, Curtis -- though I'd think the Ceti Alphans would have to be more than "mildly" telepathic to pull off a trick like that!
Your technical skills are generally solid, though you do have some typos ("their" for "there" is a particular pet peeve of mine). My main criticism of this story is that it suffers from "talking head syndrome" -- it's basically one long conversation, with no real action to speak of. The characters spend too much time telling each other things they should already know, presumably to impart this information to the audience. This literary trick is sometimes effective, particularly when the individual being educated is young, naive and/or inexperienced, but it should be used sparingly. "Show, don't tell" -- let your audience see your world at work, and try to minimize the amount that's explained through dialogue or direct narration. A longer story, with less talking and more action and plot development, could take this same basic concept and make it more interesting to read.
As I said, the story's setting is creative and fairly interesting. It seems to me, though, that there are a few logical flaws with the Ceti Alphans' biology. First, if the aliens have no natural predators and no need to hunt for food, why would they have those big, nasty-looking claws? Evolution tends to breed out energetically expensive traits that are unnecessary for survival, while magnifying the development of those traits that give a selective advantage. The presence of huge talons indicates a species that has had to hunt or defend itself extensively, in the past if not at present. Similarly, there's no adaptive advantage in having a powerful brain unless you need to be clever in order to survive. Plants living an "idyllic existence" wouldn't become sentient, even if they had the genetic potential to develop intelligence. Idyllic lifestyles, for any species, lead to stasis, and the loss of traits not directly needed for reproduction. Evolutionary "progress" (as seen from a biased, human perspective that intelligence is a good thing) comes from conflict and struggle.
(It's also worth noting that just because particular creatures are plants doesn't mean that they don't compete. Plants compete with each other constantly -- for space, light, water and nutrients -- and they can be quite ruthless about it. I imagine that intelligent plants would have an instinctive urge to rip up or destroy any plant in their vicinity that might steal the resources they need to survive.)
From an Applicability standpoint, the aliens are the central topic of discussion in the story, even if they don't have much time "on screen", and the image of the Ceti Alphan with the human child is the focal point of the "twist" ending. However, I have deducted a couple of points because the alien's appearance is never really described, and the scene would be difficult to visualize if you'd never seen the picture.
In summary, Curtis, you've got some fairly solid technical skills and a fertile imagination. Practice expanding those ideas of yours into longer stories, with less talk and more action, and I think you'll do well in your future endeavors.
Spelling/Grammar: A-
  Technique: B
  Creativity: B-
  Artistry: C
  Applicability: C
Final Score: 35 out of 50