Item Number: SCP-199 Object Class: Euclid Special Containment Procedures: SCP-199 is contained in a cube-shaped containment chamber twenty meters on a side, equipped with artificial light suitable for plant growth.

Instances of SCP-199-2 are to be harvested pending their maturity by Class D personnel wearing Class A/Type 1 hazmat suits and breathing apparatus.

Prior to maturation and release of spores, SCP-199-2 instances are to be placed in a one cubic meter, sealed Plexiglas cube-shaped container containing ten liters of potting soil.

Once the spores are released, the plexiglass container is perforated to harvest or destroy the resulting slime mold.

Newly grown instances of SCP-199 are to be contained along with other instances.

Description: SCP-199 is an unknown fern belonging to the family Hymenopteronidae, similar to Hymenopteron, but more tolerant to changes in temperature and humidity.

The plant's rhizomes are very hardy and will grow on most solid surfaces, even on chimneys or smooth walls.

The plant's rhizome resembles a frondous liverwort in appearance, but has unique fronds.

The fronds form bladders about 10 centimeters in diameter, which are filled with hydrogen and float away from the main trunk of the plant.

The cyst, designated SCP-199-2, will float in the air and mature over several days as it absorbs sufficient energy through photosynthesis.

During this time, the spores carried by SCP-199-2 will mature, and the contents of the capsule will solidify to form a single cell resembling a protoplasmic slime mold to protect the spores within.

When mature, SCP-199-2 will explode, expelling its contents and releasing the slime mold within approximately ten meters.

The slime mold will splash over the area and immediately immobilize invertebrates and small vertebrates, and cause neurological damage to larger animals, similar to the effects of exposure to V-series neurotoxins.

Slime molds that do not land on a nutrient-containing source will slowly move toward anything nearby that they can digest, similar to an amoeba.

The slime mold then begins to rapidly decompose all organic matter and produces symptoms similar to necrotizing fasciitis in large animals, while smaller animals turn into a mush within an hour.

The fertilizer it produces will feed the spores, allowing the cycle to continue.

SCP-199 is highly resistant to most defoliants and appears to thrive in contaminated environments.

However, since the plant separates hydrogen gas from water through a unique catalytic process, SCP-199 is explosive when exposed to fire and can be controlled through careful incineration.

Uncontrolled burning can result in collateral damage and the release of immature slime mold.

Personnel responsible for incineration are required to wear protective clothing underneath a fire-resistant Class A/Type 1 hazardous materials handling suit.

Foundation medical personnel are required to be prepared to distribute butyrylcholinesterase and atropine to affected personnel as quickly as possible, and to terminate them immediately if drugs are unavailable.

Survivors will have their affected areas cleaned and receive intravenous antibiotics for two weeks.

Severe wounds that do not respond to treatment may require amputation or, in extreme cases, euthanasia.

All deceased are to be incinerated within four hours of exposure unless overridden by O5 order.

Addendum 199-a: SCP-199 was first discovered in the ██████ Province of the Republic of China, where several instances were seen growing on the chimneys of manufacturing plants, steel plants, and thermal power stations.

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Several deaths due to unknown contaminants prompted local investigators to investigate the substance and contact the Foundation.

Addendum 199-b: Several insect species have been introduced into SCP-199's environment as backup control options.

In each experiment the insects died shortly after being exposed to the plant or trying to eat it.

The slime mold's precursors are very effective as pesticides, and research is currently underway on how to safely harvest these precursors for use in destroying plant or arthropod SCPs.

Addendum 199-c: Recent intelligence indicates that the Chaos Insurgency was involved in the creation or dissemination of SCP-199.

Evidence points to the possibility that SCP-199 is a man-made weapon used by certain groups for eco-terrorism.