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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
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North American Species of Cactus
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 or cespitose）； but
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North American Species of Cactus
sometimes slender…cylindrical； covered with spine…bearing tubercles：
flower…bearing areola axillary （with reference to tubercles）； entirely
separate from the terminal spine…bearing areola； although sometimes
（Coryphantha） connected with it by a woolly groove along the upper face
of the tubercle： ovary naked： seeds smooth or pitted： embryo usually
straight； with short cotyledons。 Originally defined by Linnaeus in his
Systema； ed。 l （1735）。
The Linnaean genus Cactus of 1753 included 22 species and was
coextensive with the present order。In 1812 the species were separated by
Haworth into five genera； the original generic name Cactus being
discarded。Among these species C。 mamillaris seems to have stood as the
type； not only of the Linnaean genus Cactus； but also of Haworth's
Mamillaria； and as such should retain the original generic name。Besides；
Mamillaria was used as the generic name of an alga in 1809。Cactus
mamillaris L。 is the West Indian Mamillaria simplex Haw。
From one point of view the two sections of the genus （Eumamillaria
and Coryphantha） deserve generic separation； for the character of
grooveless and grooved tubercles seems to hold without exception； and the
sections are separated with more certainty than are certain species of
Coryphantha and Echinocactus。If genera are simply groups of
convenience the separation should be made。
I。 EUMAMILLARIA。Flowers from the axils of the older or full…grown
tubercles （hence usually appearing lateral）； mostly small； and generally
from whitish to pink or red： tubercles never grooved： fruit almost always
clavate and scarlet。
A。 Tubercles more or less quadrangular。
*Central spines not hooked。 ＋More than one central spine。
1。 Cactus alternatus； sp。 nov。
Subglobose； 10 cm。 in diameter； simple： tubercles long （15 to 20 mm。）
and spreading； with woolly axils： radial spines 3； rigid and recurved； 5 mm。
long； central spines 3； very stout and much recurved； 20 to 30 mm。 long；
alternating with the radials； all ashy colored and often twisted： flower and
fruit unknown。Type in Herb。 Coulter。
The few spines； with the very short radials alternating with the very
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North American Species of Cactus
long and stout centrals； furnish a striking character。 Occasionally one of
the centrals is wanting。
2。Cactus acanthophlegmus （Lehm。） Kuntze； Rev。 Gen。 Pl。 260
（1891）。
Mamillaria acanthophlegma Lehm。 Delect。 Sem。 Hamb。 （1833）
Subglobose w