Mammillaria of the Month

(click here for previous Mamms of the Month)

Mammillaria compressa ssp. compressa

Mammillaria compressa ssp. compressa Repp. 790  (bernalensis), in cultivation.  Copyright Chris Davies 2013  

Mammillaria compressa is a well known species, although it is often mistaken for Mammillaria magnimamma. Both species are widely distributed from the states of Hidalgo northwards to Tamaulipas, and westwards to Queretaro. The species itself is really only found in Hidalgo and Queretaro, and a subspecies, ssp. centralifera, will feature next month.

It is a variable species, and one that readily offsets and grows steadily, filling in time as large a pot or pan as you might like to put it in. The spines vary in length, usually chalky white with brown tips, mostly centrallplaced, 4 to 6 in number typically, the lower being the longer. It often has bristles from the axil, which is sometimes the only distinguishing feature between it and Mammillaria magnimamma.

It flowers quite readily, and bright purple-pink rings around each head make this species a beautiful one at flowering time, which is usually May to June.

The plant in the photo is one that was originally named as Mammillaria bernalensis, long since subsumed into Mammillaria compressa., and which I won at my very first Mammillaria Society Annual meeting in a raffle. Those were the days when 30-40 people came to Anual Meetings (HINT!!).

The photo below clearly shows the axillary bristles, as said before, a key distinguishing characteristic of this species.