Coryphantha bumamma is a strongly offsetting species forming
large groups up to 50 cm in diameter. In adulthood it produces an
abundant amount of attractive wool that covers its body. This will wash
off if watered from above but will re-grow again. It is very similar to
C. elephantidens but the flower are much smaller and nearly yellow.
It has a stout carrot-like root ,
almost equal in diameter to that of the stem itself.
broader than high, often
(in habitat) arising only a little above the surface of ground, glossy
green to bluish-green up to 13 cm in diameter.
Tubercles: Very large up
to 27 mm wide and 16 mm tall, always broader than rounded, in 8-13
series, conical flattened , rounded on top, slightly pentaedrical at the
base, with a woolly groove on the upper side. The axil in youth is very
woolly, later naked. Without glands.
Elongate up to 4 mm long.
Radial spines: The
tubercles are capped with a 5-8 of stout, stiff, evenly spreading,
reflexed radial spines,16-26 mm long, subulated, curved, never porrect,
but adpressed to the body, usually 3 more strong are on the sides greysh
or brownish with darker tips
Flowers: Sweet smelling
large 5 to 6 cm
yellow with reddish midstripe dorsally, inner perianth segments narrowly
oblong to lanceolate, margin entire, acute, 5 mm wide, filament
reddishat the base, lobes greenish, stigma longer then filaments.
The flowers generally appear mid to
Fruits: Claviform, very big, ca. 4 cm long, 10-13 mm
diameter, whitish green with a reddish tinge.
Seeds: About 4 mm long and 1 mm in
diameter, light brown.