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imbricate； 12 to 18 mm。 long and about as wide at base； the upper surface
convex and variously fissured （presenting an irregular warty appearance）
even to the edges： flowers apparently central； about 2。5 cm。 long and
broad； shading from whitish to rose： fruit oval； pale green； about 10 mm。
long： seeds 1。6 mm。 long。 （Ill。 Bot。 Mex。 Bound。 t。 16）Type unknown； but
specimens of Wright； Bigelow； and Parry in Herb。 Mo。 Bot。 Gard。 are the
basis of Engelmann's Mamillaria fissurata。
On limestone hills； in the 〃Great Bend〃 region of the Rio Grande in
Texas； and southward into Coahuila。Fl。 September…October。
Specimens examined： Texas （Wright of 1850； Bigelow of 1852； Parry；
with no number or date； Lloyd of 1890； Evans of 1891； Briggs of 1892）：
also growing in Mo。 Bot。 Gard。 1893。
This species is very closely related to the Mexican A。 kotchubeyi Lem。
（A。 sulcatum Salm…Dyck）； but unfortunately no type of that species seems
to be in existence； and Dr。 Engelmann notes （Mex。 Bound。 Rep。 75） that
〃it seems no living or dead specimen is at present extant in
Europe。〃Judging from the description； the upper surface of the tubercles in
A。 kotchubeyi； aside from the central furrow； is smooth； at least the margin
is 〃very entire。〃
** Upper surface of tubercle not grooved； but usually with atomentose
pulvillus at the tip。
2。 Anhalonium prismaticumLem。 Cact。 1 （1839）。
Mamillaria prismaticaLem。 Hort。 Univ。 i。 231 （1839）。Cactus
prismaticusKuntze； Rev。 Gen。 Pl。 261 （1891）。
Flat above； top…shaped below； 7。5 to 12。5 cm。 in diameter： tubercles
（upper portion） close＇y imbricate but squarrose… spreading； sharply
triangular…pyramidal and very acute （with a sharp cartilaginous tip； which
usually disappears with age and leaves the older tubercles blunt or retuse）；
18 to 25 mm。 long and about as wide at base； the upper surface almost
plane and smooth； except that it is more or less pulverulent and usually
bears a small tomentose pulvillus （often evanescent later） just behind the
claw…like tip： flowers rose…color： fruit elongated… oval and reddish。 （Ill。
Lem。 Cact。 t。 1。）Type unknown。
Referred to Mexico in general； but reported definitely only from San
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North American Species of Cactus
Luis Potosi。Undoubtedly found in Coahuila； and possibly crosses the Rio
Grande in the region of the 〃Great Bend。〃
Specimens examined： San Luis Potosi （Eschanzier of 1891）： Mexico
in general （specimens from Coll。 Salm…Dyck in 1858； Schott of 1858）：
also specimens cultivated in Mo。 Bot。 Gard。 in 1881； also growing in same
garden in 1893。
3。 Anhalonium furfuraceum（Watson）。
Mamillaria furfuraceaWatson； Proc。 Amer。 Acad。 xxv。 150 （1890）。
Very closely related to prismaticum； but triangular portion of tubercle
acuminate and shorter； having an irregularly mamillate upper surface； and
the acumination ending abruptly in a cartilaginous depression containing a
tomentose pulvillus： flowers 2。5 to 3 cm。 long； white or pinkish； the sepals
brownish。 Type； Pringle 2580 in Gray Herb。
At Carneros Pass； Coahuila。
Specimens examined： Coahuila （Pringle 2580 of 1889）。
The type of this species was not among the collections received from
Cambridge； but a specimen of the same distribution from the National
Herbarium shows tubercle dimensions different from those recorded in Dr。
Watson's description。In that description the triangular terminal surface is
said to be 〃about an inch broad by one…half inch；〃 which is decidedly
different from the equilateral surface of the tubercle of prismaticum。In the
National Herbarium specimen of furfuraceum； however； of the same
distribution； the surface is almost equilateral； measuring 15 mm。 long by
18 mm。 wide at base。Without the acuminate upper portion the breadth of
the triangular portion would be about double its length。The lower rim of
the cup…like depression which terminates the tubercle and contains the
pulvillus is sometimes slightly prolonged into a tooth； which in
prismaticum becomes the sharp tip of the tubercle。The 〃minutely
furfuraceous…punctulate〃 character of the tubercle is common to all the
species of Anhalonium I have seen； and simply represents the external
openings of the remarkably long cuticular passageways to the stomata。
4。 Anhalonium pulvilligerumLem。 Cact。 （1839）。
Anhalonium elongatumSalm…Dyck （1850）。
This seems to be a third grooveless Mexican species。I have seen no
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North American Species of Cactus
specimens； but judge from the description that it differs from the two
preceding species chiefly in its less crowded and more elongated tubercles
（triangular portion 5 cm。 long by 2。5 cm。 broad at base）； which are
covered at apex with a tomentose pulvillus。
GEOGRAPHICAL
DISTRIBUTION。
This curious genus is strictly Mexican； and； so far as at present
recorded； is characteristic of Coahuila； but a single species （engelmanni）
of the four or five known crossing the Rio Grande in the Great Bend。
3。 LOPHOPHORA；gen。 nov。
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