MRRL (Melmak Revert): what a revert is and why it matters

01What MRRL is

MRRL is an isolated Psilocybe cubensis line in the Mushrealm collection, catalogued as MRRL (Melmak Revert). A revert is a line that has returned to an earlier, usually pigmented, form from an albino or mutant parent. The library carries another one, BAPER (Blue APE Revert), and the convention is the same in both: the word records the history of the line rather than describing the mushroom.

02Lineage and history

Melmac is one of the older names in the hobby, a Penis Envy-family line whose own early history is oral rather than written. Lines derived from it, including the albino forms, carry the Penis Envy traits of a thick stem and a thin spore deposit. True Albino Melmak (TAM) is the fully unpigmented form the library also lists.

A revert is what happens when a line that had been selected towards albinism throws a pigmented expression again, and a breeder chooses to keep and stabilise that. MRRL is the Mushrealm isolate of exactly that event. The catalogue does not publish which generation the revert appeared in, so this guide does not put a number on it.

03Under the microscope

Pigment is the point. MRRL spores are the ordinary cubensis form, subellipsoid and thick-walled with a germ pore, and they carry normal purple-brown pigment, so a print from the line reads as a standard cubensis deposit rather than the pale grey of an albino card.

The exercise is a paired slide. Put MRRL beside an albino line from the same broad family, an APE isolate or an ABV, at the same objective and the same light level. One drop resolves easily; the other needs the diaphragm closed and the lamp lowered. That is what pigment does, demonstrated in a single sitting, and it is much clearer with a revert than with two unrelated lines.

04Where to buy MRRL in the UK

MRRL is in stock now. The card is MRRL spore syringe in the strain library. Every syringe is a 10 ml luer-lock, filled in a flow hood from a logged print into sterile water, capped, labelled with the strain and its LOT, and refrigerated until it is packed.

• Price: isolated lines are listed at £20 per syringe. The card shows the current price, including any sale.
• UK shipping: £3.80, and free on orders over £75. US orders ship at a flat $8.
• Dispatch: one to two working days from the UK, tracked, in a plain padded mailer with no branding on the outside.
• Every order is 18+ and confirms lawful microscopy use at checkout.

Browse the rest of the collection on the Mushrealm and A.C.S chapter, or open the strain library to filter by species, format or isolation status. If anything arrives cloudy or damaged, email a photo and the LOT number and it is replaced.