Rebutia muscula, often called the "Little Mouse Cactus" or "Orange Snowball," is a charming and popular small cactus prized for its dense covering of white spines and profusion of bright orange flowers. Here's a detailed look:  
 
Appearance:
Stems: Forms low, clustering mounds or cushions of small, globular to slightly elongated stems, typically reaching about 2-5 cm in diameter. These stems lack prominent ribs but are covered in closely packed tubercles arranged in spiral patterns.  
Spines: The most distinctive feature is its dense covering of short, fine, white, hair-like spines. These spines are so numerous and closely set that they often obscure the green body of the cactus, giving it a soft, fuzzy, "snowball" appearance, hence one of its common names.  
Areoles: The areoles (the points from which spines grow) are small and produce many spines.  
Flowers: Produces an abundance of vibrant, funnel-shaped flowers that are usually a striking orange to reddish-orange. These flowers are relatively large for the size of the plant, often appearing in late spring to early summer and sometimes blooming repeatedly. They emerge from the sides of the stems, near the base.  
Roots: Has a relatively fine root system.
 
Native Habitat:
Native to the high-altitude regions of Bolivia in South America.  
 
Cultivation and Care:
Light: Rebutia muscula thrives in bright, direct sunlight but can also tolerate light shade, especially during the hottest part of the day. Adequate light is crucial for maintaining its compact growth and encouraging abundant flowering. Indoors, a south-facing window is ideal.  
Temperature: Prefers moderate temperatures during the growing season (spring and summer). It benefits from a cool and dry winter rest (around 5-10°C or 41-50°F) to stimulate spring blooming. It is somewhat cold-hardy if kept dry, reportedly tolerating short periods down to -4°C (25°F), but it's best to protect it from prolonged freezing.  
Watering: During the active growing season, water thoroughly when the soil has completely dried out. Reduce watering significantly in the fall and keep it mostly dry during the winter rest, watering very sparingly only if the stems show signs of shriveling. Overwatering is a primary cause of root rot in rebutias.  
Soil: Requires a well-draining cactus and succulent potting mix. A mix with plenty of added perlite, pumice, or sand will ensure proper drainage and aeration.  
Potting: Repot in spring when the plant outgrows its container. Ensure the new pot has drainage holes. As it's a clustering species, you can either repot the entire clump or divide it.  
Fertilizing: Feed once or twice during the growing season with a diluted, low-nitrogen, high-potassium cactus fertilizer. Avoid over-fertilizing.
Air Circulation: Good air circulation is important to prevent fungal issues.  
 
Propagation:
Offsets (Pups): Rebutia muscula readily produces offsets, which is the easiest way to propagate it.
Carefully detach the offsets from the main plant once they are a reasonable size.
Allow the cut surfaces to callous over for a few days in a dry place.  
Plant the calloused offsets in well-draining cactus soil.  
Water lightly at first until roots establish.
 
Seeds: Can also be grown from seed sown in a well-draining seed-starting mix. Keep warm and slightly moist until germination.
 
Key Features and Distinctions:
Dense White Spines: Gives it a unique, fuzzy appearance.
Prolific Orange Flowers: Produces a large number of bright orange, funnel-shaped flowers.
Clustering Habit: Forms attractive clumps over time.  
Relatively Easy to Grow: Considered a good cactus for beginners.  
Needs Winter Rest: A cool, dry winter period is important for flower production.
 
Rebutia muscula is a rewarding cactus to grow, offering a delightful contrast between its soft-looking spination and vibrant floral display. Its ease of propagation and relatively low maintenance make it a popular choice for cactus enthusiasts of all levels.
 
 
* Picture and information intended only as a guide.  Size and colours of plants will vary, not any 1 plant is exactly the same and minor variations will occur.
 
** All plants will be posted bare rooted.