The North American Species of Cactus, Anhalonium, and Lophophora | Page 4

been impossible.
(2) Those of the Department of Agriculture, including the results of
several recent explorations, for the use of which I am indebted to Mr.
Frederick V. Coville.
(3) Those of the Gray Herbarium at Harvard University, which Dr. B. L.
Robinson kindly placed at my disposal.
(4) Those of the California Academy of Sciences, notably rich in forms
from Lower California and the adjacent islands, kindly loaned by Mr. T.
S. Brandegee.
(5) Those of Dr. Louis Eschanzier, of San Luis Potosi, Mexico, who
send a large series of Mexican forms collected in 1891.
(6) Numerous small sets from different correspondents, who have given
both time and material in aiding the work.
It is needless to say that Dr. George Engelmann, the great pioneer
student of this difficult family, has opened the paths in which we must
follow, and it was exceedingly unfortunate that he was not able to
complete the final revision that he had in mind.
The difficulties which beset the critical study of this group can not be
easily exaggerated. Such scanty material as has been collected has been
for the most part very incomplete, consisting of plant bodies without
flower or fruit, flower or fruit without plant bodies, and bunches of
spines without either. The species are displayed also in the most
inaccessible regions, and their culmination is found in the still poorly
known regions of Mexico.
On account of their singular forms and often brilliant flowers they have

long been extensively cultivated, especially in Europe. These cultivated
forms have formed the basis of original descriptions in almost all of the
European publications, and in very rare cases have any types been
preserved. As a result, the bibliography of Cactaceae is appalling, and it
is questionable whether satisfactory conclusions can be reached in the
case of hundreds of published names. The earlier descriptions were not
only meager, but were based upon what are now regarded very
insufficient characters, and in the absence of types it is not only unsafe,
but impossible to venture an opinion concerning their identity. In view
of these facts, I have thought it advisable to present a preliminary
revision of the order, which shall contain the results of the study of
material confessedly insufficient. With such knowledge as we possess
brought together, it is hoped that the study of this very interesting and
much neglected group will be stimulated, and that more critical
exploration of our southwestern territory and adjacent Mexico will
make a more satisfactory presentation possible. It would be useless to
notice the vast number of reputed species that are not represented by
actual specimens in our possession.
In the proposed preliminary account of the family, of which the present
paper is the first part, only those genera are considered which form a
part of the flora of the United States, and those species which I have
been able to examine and to identify with reasonable certainty. All
forms credited to the United States have been studied, and the account
of these species may be considered fairly complete, but the far more
numerous Mexican species are but scantily represented. The Mexican
boundary is so unnatural a dividing line in the distribution of Cactaceae
that it has been disregarded, and all the species studied have been
arranged in a lineal series of uniform prominence. So far as known the
subject of geographical distribution is considered, but it will be seen
how meager is our knowledge of this subject. It is to be hoped that this
preliminary presentation will provoke exploration and study, and that
species will not only be collected, but all the facts of their distribution
noted. It is more than probable that our present notion of species in this
group must be much modified, and doubtless many forms are at present
kept specifically distinct which will prove to be but different phases of
a single species.
In the matter of generic delimitation we are in still greater uncertainty,

and several generic lines at present recognized must be regarded as
purely arbitrary, a fact which must become still more evident with
additional material. The whole group is to be regarded as made up of
poorly differentiated forms and only long observation under cultivation
can determine the possibilities of specific variation under the influence
of environment, of age, of inherent tendencies. For instance, that these
plants change in form and in spine characters with increasing age and
after they have begun to flower can not be doubted, but what described
forms have thus been separated in descriptions can only be guessed at.
John M. Coulter. Lake Forest University, Lake Forest, Ill., January,
1891.

CACTUS, ANHALONIUM, AND LOPHOPHORA.
1. CACTUS Linn. Sp. Pl. 466 (1753), restricted.
MAMILLARIA Haw. Synop. 177 (1812), not Stackh. (1809).
Usually globose to oblong plants (simple, branching