For the Flora of North America project, we were asked by Nancy Morin to
expand upon an earlier accounting for the U.S.A.
to include all of North America. Following is
a modified and supplemented version of the abstract that appeared in the
publication.
Taxonomic Novelties from North
America north of Mexico:
A 20-Year Vascular Plant Diversity
Baseline
By
Ronald L. Hartman and B. E.
Nelson
1998. Monographs in Systematic Botany from the Missouri Botanical Garden
67: 1--59.
ABSTRACT
A survey of the literature and the Gray Herbarium Card and Kew indices was
performed to determine the number of taxa new to science published in North
America north of Mexico
from 1975 through 1994. A total of 99 families were represented, although 34
contained 1025 taxa (85.9% of the total). Five genera, Apacheria, Cochiseia,
Dedeckera, Shoshonea, and Yermo, and one nothogenus, HDryostichum,
were based solely on newly described species. New species and terminal
infraspecific taxa were distributed as follows: pteridophytes with 78 (6.5%),
gymnosperms with 6 (0.5%), and angiosperms with 1113 (93%) for a sum of 1197
(59.85 taxa or 27.9 species per year). During this 20-year period, the
five-year averages for the publication of new species were 28, 35.6, 26.2, and
30.8. Comparable averages for subspecies and varieties were 7.8 and 14.8; 7 and
16; 5.8 and 17; 7.2 and 14.8, respectively. The total number of new subspecies
proposed as terminal taxa was 139 (30.7%), compared to 313 (69.3%) for
varieties. Data on species for the period 1955 through 1974 are also provided
(32.1 species per year). With the exception of the years 1971 through 1974,
when more new species were proposed, the frequency of taxonomic novelties is
relatively constant over the 40-year (30 species per year). A total of 505
authors participated in the publication of the 1197
new taxa, although 11.8 percent of them authored 703 taxa (59% of total).
Ninety-one books and journals were involved, although 36 served as the outlet
for 1093 novelties. The new taxa were divided among the following categories of
study: floristics, 375 taxa; plants of conservation concern, 33; taxonomy, 703;
and biosystematics, 86. The states yielding the greatest number of holotypes
were: California, 217; Utah,
183; Texas, 70; Nevada,
63; Arizona, 57; Oregon,
42; New Mexico, 41; Florida, 38; Idaho,
33; Wyoming, 32, Colorado,
29, . . . Washington, 13, Montana, 12; British
Columbia, 9, and Alberta,
3 (Rocky Mountain political entities in bold).
Likewise, the leading floristic areas, based on holotypes, were Intermountain,
287; California, 217; Rocky Mountain, 131; Southeast, 113; Southwest,
107, Texas, 70, Canada, 62, Northwest, 64, and Northeast 51. It is concluded
that the resurgence of biodiversity studies, as well as the efforts of
monographers and contributors to regional floristic projects and to Flora of
North America (FNA), will help maintain the current level of publication of
novelties, but that within the next 10 to 15 years the discovery of previously
unknown taxa is likely to decrease.
Stated differently, this is both a reflection of the amount of floristic and
taxonomic work being done by state or region as well as the amount of continued
investigatioon warranted. A more extensive discussion of floristic surprises in
North America and a review of the
justification for floristic research may be found in Ertter (2000).
Ertter, B. 2000. Floristic surprises in North America north of Mexico. Ann. Missouri
Bot. Garden. 87: 81--109.
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