A+

Abstract

Psilocybe cubensis ‘A+’ is a widely cultivated psychoactive mushroom strain known for its distinctive leucistic phenotype, moderate potency, and vigorous growth. It is characterized by pale, sometimes nearly translucent caps and slender, elongated stipes that exhibit strong blue bruising when handled. The A+ strain is particularly valued for its reliable performance, ease of cultivation, and visually striking appearance during fruiting. This entry reviews the organism’s morphological traits, spore characteristics, developmental behavior, and environmental requirements, with emphasis on its suitability for both novice and experienced cultivators seeking a visually unique and dependable strain within the P. cubensis complex.

1. Introduction

A+ is a cultivar of Psilocybe cubensis that has gained popularity for its leucistic expression, producing fruiting bodies with reduced pigmentation and pale coloration. Although often referred to as "albino," A+ does not exhibit true albinism but rather a significant lack of melanin, resulting in characteristic pale caps and white to off-white stems. This strain is widely regarded for its vigorous colonization, robust mycelial growth, and consistent fruiting patterns, making it highly suitable for both traditional PF Tek and advanced grain-to-bulk cultivation methods. While genetically aligned with other P. cubensis strains, A+ stands out due to its distinctive appearance and reliable performance.

2. Gill Formation

A+ produces gills that are initially pale grey and gradually darken to purplish-brown as spores mature. Gill attachment is typically adnate to adnexed, with moderately spaced, broad lamellae. The fertile hymenium supports prolific spore production in mature specimens, though paler gill coloration in early stages is characteristic of leucistic strains.

3. Microscopy and Spore Morphology

Basidiospores are ellipsoid to subellipsoid, smooth-walled, and dark purplish-brown in mass deposit. Dimensions typically range from 7–12 µm in length. Spore prints are abundant and clearly visible despite the pale appearance of the fruiting body. Microscopic analysis reveals typical P. cubensis features, including clamp connections, pleurocystidia, and cheilocystidia. Hyphal structures in the pileipellis display gelatinization consistent with other leucistic forms.

4. Macromorphology

4.1 Cap (Pileus)

Caps measure 40–70 mm in diameter and exhibit a convex to plane morphology with maturity. The coloration ranges from creamy white to very pale golden hues, sometimes with subtle bluish or grayish tones, particularly under high humidity. The cap surface is smooth, often slightly translucent when fresh, and may show faint radial fibrils. A slight umbo may be present in some specimens.

4.2 Stipe (Stem)

Stipes range from 100–200 mm in height, slender to moderately thick, and white to pale cream in coloration. Prominent blue bruising occurs upon physical disturbance due to psilocin oxidation. Younger specimens exhibit solid stipes, while larger, mature mushrooms may develop a hollow core. Mycelial tufts are often present at the base.

4.3 Performance Characteristics

A+ is known for vigorous colonization speeds and strong rhizomorphic mycelium. It consistently produces moderate to large flushes with high resilience to minor fluctuations in humidity and temperature. This strain is particularly responsive to well-prepared substrates and benefits from controlled environments with stable hydration.

5. Nutritional Substrates and Cultivation Conditions

5.1 Primary Substrates

A+ is nutritionally flexible and thrives across a range of standard cultivation substrates.

• Brown Rice Flour (BRF) + Vermiculite (PF Tek):
• Ideal for beginners seeking reliable results.
• Offers adequate nutrition and moisture retention through vermiculite.
• Grain Spawn (e.g., Rye Berries, Millet, WBS):
• Supports faster colonization and larger yields.
• Preferred for spawning into bulk substrates to maximize output.

5.2 Bulk Substrates

Optimal performance is achieved on pasteurized bulk substrates that offer structural support and balanced hydration.

• Coco Coir + Vermiculite + Gypsum: Provides reliable hydration and structure with minimal contamination risk.
• Manure (Cow/Horse): Enhances nutritional richness, supporting denser fruiting.
• Straw: Requires pasteurization and often combined with coir or manure for improved performance.
• Compost: Suitable for advanced growers familiar with contamination management.

5.3 Additives and Supplements

• Gypsum (CaSO₄): Improves texture and balances pH.
• Worm Castings: Enhances microbial biodiversity and nutrient profile.
• Spent Coffee Grounds: Use sparingly due to increased contamination risk.

6. Fruiting Parameters

• Colonization Temperature: 75–81°F (24–27°C)
• Fruiting Temperature: 70–77°F (21–25°C)
• Relative Humidity: 85–95% RH during fruiting
• CO₂ Levels: Reduced via regular fresh air exchange to promote pinning
• Light: Indirect, diffuse light on a 12/12 schedule aids orientation and development

7. Summary

A+ is a highly regarded Psilocybe cubensis strain known for its leucistic appearance, reliable fruiting, and vigorous growth. Its pale, nearly translucent caps and slender, white stems distinguish it visually from standard pigmented strains, while its performance remains consistently robust across a variety of cultivation methods. A+ is well-suited to cultivators of all experience levels, offering a forgiving yet visually striking option within the broader P. cubensis genetic spectrum.