Articles
Correct Author Citation for Cirsium eatonii var. Eriocephalum (Asteraceae: Cardueae), SIDA Contributions to Botany (2005)
Diploid and Polyploid Cytotype Distribution in Melampodium cinereum and M. leucanthum (Asteraceae, Heliantheae) (with Tod F. Stuessy and Hanna Weiss-Schneeweiss), American Journal of Botany (2004)
Previous chromosomal studies within Melampodium (Asteraceae, Heliantheae) of Mexico and Central America have documented chromosome...
New Taxa and New Combinations in North American Cirsium (Asteraceae: Cardueae), SIDA Contributions to Botany (2004)
Six new varieties are proposed in North American Cirsium (Asteraceae: Cardueae): C. arizonicum (A. Gray)...
Two New Species of Pectis (Asteraceae: Tageteae) from South America, Novon (2002)
Pectis hassleri and P. pumila are new species, the former from the Gran Chaco area...
Review of A Manual of California Vegetation by J. Sawyer & T. Keeler-Wolf, Systematic Botany (1997)
New Combinations in Gnaphalium (Asteraceae: Inuleae) (with G. Ledyard Stebbins), Novon (1992)
Because of extensive morphological intermediacy, plants formerly distinguished at the species level as Gnaphalium...
Documented Chromosome Numbers 1990: 1. Miscellaneous North American Vascular Plants (with Bruce D. Parfitt, Donald J. Pinkava, Debbie Rickel, Dan Fillipi, and Beth Eggers), SIDA (1990)
The following meiotic chromosome counts are documented by specimens deposited in Herbarium of Arizona State...
Porophyllum pygmaeum (Asteraceae), a Distinctive New Species from Southern Nevada (with James D. Morefield), Systematic Botany (1989)
Porophyllum pygmaeum is a new species from coarse calcareous soils of the Desert National Wildlife...
Plant Photosensitizers: A Survey of Their Occurrence in Arid and Semiarid Plants From North America (with Kelsey R. Downum, Sergio Villegas, and Eloy Rodriguez), Journal of Chemical Ecology (1989)
Chromosome Studies in Asteraceae from the United States, Mexico, the West Indies, and South America (with Melissa A. Luckow and Donald J. Pinkava), American Journal of Botany (1988)
Chromosome counts of Asteraceae are reported from Mexico, the United States, the West Indies, Peru,...
Synopsis of the Florida Species of Pectis (Asteraceae), SIDA (1986)
A key, descriptions, revised nomenclature, range statements and maps ate presented for the species of...
Lectotypification of Pectis L. (Asteraceae), Taxon (1985)
Linnaeus (1975a) described Pectis and included within it two species, P. ciliaris and P....
New Species of Pectis (Asteraceae) from the West Indies, Mexico, and South America, Brittonia (1984)
Four new species of Peetis are described: P. ericifolia from Barbuda, P. luckoviae from west-central...
Systematics of Isocarpha (Compositae: Eupatorieae) (with Tod F. Stuessy), Systematic Botany (1981)
Isocarpha comprises five species ranging from southern Texas and the Bahamas to northern Peru and...
A Revision of Pectis Section Pectothrix (Compositae: Tageteae), Rhodora (1978)
Pectis L. sect. Pectothrix A. Gray (Compositae: Tageteae) comprises a group of showy, yellow-headed species...
Chromosome Counts of Compositae from Mexico and the United States, American Journal of Botany (1977)
Chromosome counts of Compositae are reported from Mexico and the United States. First generic counts...
Chromosome Counts of Compositae from the United States and Mexico (with Donald J. Pinkava), American Journal of Botany (1977)
Chromosome counts are reported for 126 taxa representing 122 species and 61 genera of Compositae....
Chromosome Studies in North and Central American Species of Pectis L. (Compositae: Tagetaea), Rhodora (1977)
Chromosomal modification is often a major factor in the evolutionary diversification of a large, rapidly...
Clematis coahuilensis (Ranunculaceae), a New Species from North-Central Mexico, Bulletin of the Torrey Botanical Club (1977)
Floristic investigations in the Cuatro Cienegas basin and nearby mountain ranges in Coahuila, Mexico, have...
Revision of Pectis Section Pectidium (Compositae: Tageteae), Rhodora (1977)
Pectis L. sect. Pectidium (Less.) A. Gray is a small but very wide-ranging group of...
Chromosome Counts of Compositae From the United States, Mexico, and Guatemala (with Tod F. Stuessy), Rhodora (1975)
Chromosome numbers can be extremely useful in systematic studies, particularly for helping to reveal evolutionary...
New Taxa in Pectis (Compositae: Pectidinae) from Mexico and the Southwestern United States, Brittonia (1974)
This paper is the first of a series of investigations on the systematics of Pectis...