David G. Anderson

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ACKNOWLEDGEMENTS The information in this report draws from the specimens and collection label information resources of the Rocky is a botanist with the Colorado Natural Heritage Program (CNHP). Mr. Anderson's work at CNHP includes inventory and mapping of rare plants throughout Colorado, mapping weeds, maintaining and updating CNHP's database, and writing(More)
Their interest in the project and time spent answering questions were extremely valuable, and their insights into the distribution, habitat, taxonomy, and ecology of Ipomopsis polyantha were crucial to this project. Thanks also to for assisting with questions and project management. Jane Nusbaum and Barbara Brayfield provided crucial financial oversight.(More)
Ipomopsis globularis (Globe gilia), and Saussurea weberi (Weber's saussurea) are globally imperiled plant species known only from geographically restricted areas in alpine habitats of the Rocky Mountains. These species were observed in the Mosquito Range of Colorado to determine the diversity of insect visitors (potential pollinators) and approximate insect(More)
The CUR matrix decomposition and the related Nyström method build low-rank approximations of data matrices by selecting a small number of representative rows and columns of the data. Here, we introduce novel spectral gap error bounds that judiciously exploit the potentially rapid spectrum decay in the input matrix, a most common occurrence in machine(More)
In the summers of 2002 and 2003 the Colorado Natural Heritage Program (CNHP) mapped 14 selected noxious weeds found on the U.S. Air Force Academy (" the Academy ") and the Farish Outdoor Recreation Area (" Farish "). The project was undertaken to provide the U.S. Air Force Academy Department of Natural Resources with information on noxious weeds to serve as(More)
Waters and Stafford (Reports, 23 February 2007, p. 1122) provided useful information about the age of some Clovis sites but have not definitively established the temporal span of this cultural complex in the Americas. Only a continuing program of radiometric dating and careful stratigraphic correlations can address the lingering ambiguity about the(More)
In the summers of 2002 and 2003 the Colorado Natural Heritage Program (CNHP) mapped 14 selected noxious weeds found on the U.S. Air Force Academy (" the Academy ") and the Farish Outdoor Recreation Area (" Farish "). The project was undertaken to provide the U.S. Air Force Academy Department of Natural Resources with information on noxious weeds to serve as(More)
Buchanan et al.'s (1) statistical evaluation of radiocarbon dates as a demographic proxy depends on accurate and complete datasets. However, their database is incomplete for the Southeast, where 181 radiocarbon dates from Paleoindian and Early Archaic deposits are now available (2). Only a fraction of these are included in their analysis. Within the more(More)