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Yellow Umbo — Cloud920® Ready-to-Grow Bag
Yellow Umbo is the world's first interspecies Psilocybe hybrid — a cross between P. cubensis 'Jack Frost' and the newly discovered P. ochraceocentrata (formerly known as NSS/Transkei). Rated ★★★★★★ (6/6) for potency, with a smoother onset and more visual clarity than standard cubensis. Available exclusively here since 2025.
Availability: Less than 10 in stock
€45.00
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Product Description
Details
Yellow Umbo is the first documented interspecies hybrid in the Psilocybe genus — a cross between two species that have been evolving separately for 1.5 million years. One parent is Psilocybe cubensis 'Jack Frost', the strongest cubensis in our catalogue. The other is Psilocybe ochraceocentrata, a newly described species from southern Africa that scientists formally named in March 2026. No other grow kit in the world offers this combination. We have been the exclusive supplier since early 2025.
Part of the Cloud920® Genetic Series — Hybrid Fusion
Origin & Genetics
Yellow Umbo was created by mycologist Yoshi Amano in collaboration with Kilor Diamond. They isolated monokaryons from both parent species using serial streaking, developed custom microscopy methods to verify each pairing step, and had the final cross validated by Imperial Labs through interspecific verification testing. The result is a true interspecies hybrid — not just a cross between two cubensis strains, but a combination of two genetically distinct species.
The cubensis parent, Jack Frost (TAT × APE), contributes maximum potency and dense fruit body structure. The ochraceocentrata parent contributes aggressive colonisation speed, high contamination resistance, and a unique experience profile that users describe as clearer, more visual, and more euphoric than standard cubensis. The Yellow Umbo available today has reached the F7 generation — stabilised over seven generations for consistent results batch to batch.
New Species Discovery: Psilocybe ochraceocentrata
On 10 March 2026, a team of researchers from Stellenbosch University, Clark University, University of Utah, Duke University, and the Natural History Museum of Zimbabwe published a paper in Proceedings B of the Royal Society that formally described Psilocybe ochraceocentrata as a new species. For years, growers worldwide had been cultivating this mushroom under the names "Natal Super Strength" (NSS) and "Transkei," assuming it was a strain of P. cubensis. DNA analysis proved otherwise — it is an entirely separate species that diverged from cubensis approximately 1.5 million years ago.
This reclassification means Yellow Umbo is not just an unusual hybrid — it is the first confirmed cross between two different Psilocybe species. Here is how those species compare:
| P. cubensis | P. ochraceocentrata | Yellow Umbo ✦ | |
|---|---|---|---|
| Type | Classic magic mushroom species | Newly described species (March 2026) | First interspecies hybrid |
| Origin | Pantropical, Needs new research | South Africa (KwaZulu-Natal), Zimbabwe | Lab-created by Yoshi Amano & Kilor Diamond |
| Colonisation speed | Varies by strain | Very fast, aggressive | Fast — inherited from ochraceocentrata side |
| Contamination resistance | Varies by strain | Very high | High — inherited from ochraceocentrata side |
| Appearance | Golden-brown caps | Pale cap with ochre-yellow centre | Golden-yellow cap, pronounced umbo, chocolate gills |
| Experience | Varies — classic psychedelic | Strong visuals, mental clarity, euphoria | Clear, visual, euphoric — gradual onset, minimal body load |
Why Choose Yellow Umbo?
- Strength: ★★★★★★ (6/6) — maximum potency, but with a smoother, more gradual onset than most 6/6 cubensis strains. Users report less body load and more mental clarity.
- World exclusive — Yellow Umbo is the first documented interspecies Psilocybe hybrid. We have been the only supplier of this strain as a ready-to-grow bag since early 2025.
- Backed by science — the ochraceocentrata parent was formally described in Proceedings B of the Royal Society (March 2026). The hybrid itself was verified by Imperial Labs through interspecific testing. This is not folklore — it is documented science.
- Fast and resilient — inherits aggressive colonisation and high contamination resistance from its ochraceocentrata parent. Pins appear quickly and the mycelium fights off contaminants better than most cubensis strains.
- ⚠️ Ventilate daily from week 2 — Yellow Umbo needs more fresh air exchange than standard cubensis. Briefly open and refold the bag once a day to keep pins developing properly.
What's in the Box
- 1x Cloud920 Grow Bag — 2000cc pre-colonised substrate with active Yellow Umbo mycelium. Integrated micron filters provide passive air exchange and contamination protection.
- 1x Large bag clip — to seal the bag securely between ventilation sessions.
- 1x Rubber band — place around the substrate block to prevent unwanted side growth.
How the Cloud920 Grow Bag Works
- Open once — fold the bag open in a clean space to allow fresh air in and trigger pinning.
- Place and wait — put the bag in indirect light at 23°C. No soaking, no misting required in the first phase.
- Air daily from week 2 — briefly open and refold the bag once a day to encourage pin development. Yellow Umbo benefits from slightly more airflow than other strains.
- Harvest and repeat — twist and pull mushrooms at the base before caps open fully. Rehydrate and repeat for additional flushes.
Instructions
The Cloud920 Ready-to-Grow bag does not include printed instructions. Find the full step-by-step guide here: Cloud920 Grow Bag Instructions.
The Science Behind Yellow Umbo
Want to dive deeper into the discovery of Psilocybe ochraceocentrata, how Yellow Umbo was created, and what this means for the future of magic mushroom cultivation? Read the full story on our blog: New Magic Mushroom Species Discovered: The Science Behind Yellow Umbo.
Additional Info
Additional Info
| Productcode | MCS.GKC920.YEUM-XL |
|---|---|
| Weight (KG) | 1.4000 |
| Mushroom Strain | Yellow Umbo |
| Brand | Cloud920® Grow Bag |
| Difficulty | Very Easy |
| Size | Extra Large |
| Species | P. ochraceocentrata X cubensis |
| Origin | United States |
| Potency | High |
| Optimum cultivation temperature | 23ºC |
| Yield (from) | 200 grams |
| Yield (to) | 800 gram |
| Water Spray Needed | Yes |
Customer Reviews
7 Item(s)
per page
- Fun Review by Ivan
-
Fun experience interesting plant (Posted on 1/14/2026)Rating - OK Review by Mar
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It produces a lot of fruit. (Posted on 1/9/2026)Rating - Moderate yield but very pleasant experience Review by Silja
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The yield wasn't quite as good as with other growkits, dispite close to optimal conditions plus extra venting. (less than 500 g wet)Rating
But, from my first two tries, I can report that the experience was very very pleasant, and also, it seems that this strain is significantly more potent that garden variety strains such as Golden Teacher. So even with a lower yield, it seems you still get more bang for the buck. (Posted on 12/7/2025) - Super!!! Review by Dirk
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Ich habe inzwischen schon vier verschiedene Sorten hier bestellt und war jedes Mal sehr zufrieden. Der Yellow Umbo hat mich ebenfalls überzeugt – der Ertrag war zwar etwas geringer als bei den anderen Sorten, aber dennoch absolut zufriedenstellend. Die Qualität und die Wirkung waren super und haben meine Erwartungen voll erfüllt. Besonders hervorheben möchte ich auch den Kundenservice, der immer schnell und freundlich reagiert hat. Die Lieferung erfolgte zuverlässig innerhalb derselben Woche, was ich sehr schätze. Alles in allem bin ich mit dem Ergebnis sehr zufrieden und werde definitiv wieder bestellen. (Posted on 9/11/2025)Rating - it was quit a nice and easy experience Review by aldan
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really easy to grow and no need extra care (Posted on 8/23/2025)Rating - Yellow umbo Review by Mushbert
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So far a beautiful growing mushroom with really surprisingly low uncomfortable side effects.Rating
Not really strong.
Anyway, easy to grow and lovely. (Posted on 8/13/2025) - Great Review by lIlIlIlIlIlI
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The set up is as easy as it gets and as always the quality doesn’t disappoint which makes it a good kit for beginners and veterans alike. After two to three weeks you can expect the mushrooms to grow.Rating
The mushrooms in general are very healthy however I noticed that the bag is slightly more prone to abort fruits than others that I have worked with, which isn't a problem but the grower should check the kit for them and remove them if he discovers them. The kit also produced a couple of sidepins early on despite me doing everyhing to prevent them from doing so, but it’s no problem either if that happens you can think about removing the rubber band so the side pins have more space to grow.
In general the mushrooms stay small to medium sized, however the kit just doesn't stop producing fruits so you will have fun with it for a very long time. (Posted on 5/16/2025)
7 Item(s)
per page
Important information about Yellow Umbo — Cloud920® Ready-to-Grow Bag
- The purchase of this product is restricted to individuals who are at least 18 years old.
- By initiating a purchase, you confirm knowledge of and compliance with the legal terms regarding the product(s) in your country of residence, as well as your eligibility to acquire and hold them.
- Shipping restrictions apply to this product. Refer to Additional Info to discover our non-delivery zones.
- Engaging in the consumption of magic mushrooms is solely your responsibility, so be certain to thoroughly educate yourself about their usage and consequential effects.
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