Depressed-globose, proliferous and cespitose, tuberculate-ribbed,
unarmed plants: tubercles at first conical and bearing at summit
a flower-bearing areola with a dense tuft or short pencil of
compact erect hairs, when mature becoming broad and rounded (with
the remnant of the penicellate tuft as a persistent pulvillus in
a small central depression) and coalescing into broad convex
vertical ribs: spine bearing areolae obsolete: flowers borne at
the summit of nascent tubercles: ovary naked (that is free from
scales, but often downy): fruit and seed unknown.
These forms have been variously referred to Anhalonium and
Echinocactus, but seem to deserve generic distinction. They
differ from Anhalonium in the entire suppression of the upper
highly differentiated portion of the tubercle, in the broad and
rounded development of the lower portion, and in the coalescence
of the enlarged tubercles into broad vertical ribs. In fact, in
young specimens, the plant appears almost smooth, with shallow
furrows radiating from the depressed apex. The genus differs
from Echinocactus in the suppression of the spine-bearing
areolae, and the naked ovary. In the examination of developing
tubercles the relation to Anhalonium is evident. In the latter
genus the young tubercle bears on the summit of its pedicel-like
lower portion the tufted flower-bearing areola the modified upper
portion of the tubercle at that time appearing as a bract beneath
the flower. In Lophophora there is the same condition of things,
except that the bract-like upper portion is wanting. From this
point of view it would appear that the differences between
Lophophora and Echinocactus are intensified by the fact that the
flower-bearing areola in the former genus is to be regarded as
really lateral on a tubercle the upper part of which has
disappeared. This genus occurs abundantly in southeastern Texas,
extending southward into Mexico. Mrs. A. B. Nickels reports that
the Indians use the plants in manufacturing an intoxicating
drink, also for "breaking fevers," and that the tops cut off and
dried are called "mescal buttons."