high degree of overall competence and keen insight into the
 relationship and diagnostic characteristics of plant groups, but
 by what appears to be a disconcerting originality in the use
 of scientific names. All too often the name used by Small is not
 the same as the one employed for the same plant by other
 respected authors. Commonly the specific epithet is different,
 frequently a familiar specific name appears following an un-
 familiar generic name, and perhaps most disturbingly, in a
 sprinkling of cases, a well-known name, consistently used by
 other authors for a particular plant, is employed by Small for
 an entirely different species.
 These apparent nomenclatural peccadilloes of Small's, al-
 though a serious impediment to the user of his works, are not
 the consequence of mere whim, but stem in large part from two
 of his policies, firmly held and consistently applied. The first of
 these was his belief that if a taxonomic group is sufficiently dis-
 tinct to be worth recognizing, it should merit specific rank;
 only with great rarity did he recognize varieties or other in-
 fraspecific levels. Similarly, if a group of species shows even a
 small number of common characteristics, the group should merit
 separate generic rank. This policy yielded many segregate
 species and genera which are not recognized at those particular
 taxonomic levels by most modern authors. In this Checklist one
 need look for examples no further than the genus Selaginella, by
 most authors treated as one genus, but by Small considered to
 be divisible into true Selaginella and a segregate, Diplostach-
 yum; similarly, Small recognized Selaginella arenicola and S.
 acanthonota as two distinct species, while recent authors have
 treated them as subspecies or varieties of a single species.
 A second policy of Small's which has unfailingly caused
difficulty was his devotion to a set of rules of nomenclature, the
American Code, promulgated by his employer, Nathaniel Lord
Britton of the New York Botanical Garden. The American
Code, never fully accepted in the land of its origin, was rejected
by the botanists of Europe, and became of only historical in-
terest after the near-universal approval in 1930 of the present
International Code. Yet Small, beyond this date, consistently
used a set of rules governing the naming of plants that differed
in several significant points from the rules of the International
Code. Most striking, in terms of the number of name changes
caused by this unyielding conformity to the American Code,
are the generic names which differ in Small's works and those
of all modern authors as a result of the preservation in the