Marc A. Baker

Arizona State University | ASU · School of Life Sciences

Opuntioideae, composed of roughly 370 species, occur in almost every biome in the Americas, from seasonally dry tropical forests (SDTF) to high-elevation Andean grasslands, American deserts and temperate zones. The interrelationships among the three major clades of Opuntioideae (Cylindropuntieae, Opuntieae and Tephrocacteae) are not well resolved,...

The rare Baja California Sur endemic cactus Grusonia robertsii was originally hypothesized to be an intergeneric hybrid between G. invicta and Cylindropuntia alcahes subsp. alcahes but was described as a Grusonia due to its overall closer resemblance to G. invicta, except in the fruit. A more comprehensive analysis of the morphology and phylogeneti...

Volatile analyses of cacti have previously been performed on the flowers, fruits, and consumed stems. During our own investigations, we and others have observed that the cut stems of certain species of the Graveolens clade of Cylindropuntia emitted odors similar to those of rancid butter or cyanoacrylate. Some species of Consolea, Opuntia, Quiabent...

Premise: Although numerous phylogenetic studies have been conducted in Cactaceae, whole-plastome datasets have not been employed. We used the chollas to develop a plastome dataset for phylogeny reconstruction to test species relationships, biogeography, clade age, and morphological evolution. Methods: We developed a plastome dataset for most kno...

Chromosome ploidy and the evolution and distribution of the Cactaceae, especially in the Genera Cylindropuntia, Echinocereus, Grusonia, and Micropountia.

The circumscription of infraspecific taxa of Cylindropuntia acanthocarpa was evaluated using multivariate analysis of morphological characters, with C. echinocarpa as the outgroup. Our primary objectives were to sample and analyze sufficient morphological data to determine: 1) how populations within C. acanthocarpa might be best grouped, 2) whether...

A morphological and cytological study was conducted to elucidate the taxonomic circumscription of Cylindropuntia multigeniculata and its relationship to C. echinocarpa and C. whipplei. Morphological analyses included iterations of multivariate techniques including principle factor analysis, discriminant function analysis, and multivariate analysis...

A floristic account is provided for the cactus family as part of the vascular plant flora of the contiguous protected areas of Organ Pipe Cactus National Monument, Cabeza Prieta National Wildlife Refuge, and the Tinajas Altas Region in the heart of the Sonoran Desert in southwestern Arizona. The modern native cactus flora includes 35 taxa in 12 gen...

A gynodioecious hexaploid (n = 33), Cylindropuntia chuckwallensis M. A. Baker & M. A. Cloud-Hughes, is newly described. Populations of C. chuckwallensis extend from the Eagle Mountains of Joshua Tree National Park, through the Chuckwalla Mountains of Riverside County, to the north side of the Chocolate Mountains in Imperial County, California, USA,...

Unlabelled: • Premise of study: Taxonomic circumscription of subspecific taxa within Coryphantha robustispina was evaluated with morphological data and microsatellites. This study was the first to compare adequately sampled morphological and DNA analyses at the population level in the Cactaceae. This comparison was important to test reliability...

Chromosome counts are reported for 68 individuals in 64 taxa (including one interspecific hybrid) in 36 genera of 15 families. Of these, 11 taxa are counted for the first time.

We used discriminant analysis to assess taxonomic status of three closely related, rare taxa within the cactus genus Escobaria (E. guadalupensis, E. sneedii var. sneedii, and E. sneedii var. leei). These three taxa consist of nine isolated populations; six of these populations consist of morphologically typical specimens (i.e., similar to the type...

A multivariate analysis was performed for populations of Echinocereus (section Triglochidiatus) to facilitate the taxonomic circumscription of E. arizonicus subsp. arizonicus. Twenty-one morphological characters for 16 populations evidenced the validity of at least two subspecific taxa within E. arizonicus: E. arizonicus subsp. arizonicus and E. ar...

Chromosome numbers are determined for 514 individuals belonging to 119 taxa within Cactaceae. Nineteen taxa have chromosome numbers reported for the first time. Based on geographic, morphological, and cytological data, three new nomenclatural combinations are made: Cylindropuntia ×cardenche (GRIFFITHS) PINKAVA & M. A. BAKER, Cylindropuntia imbricat...

A florally dimorphic hexaploid (n=33), Echinocereus yavapaiensis M. A. Baker, is newly described and possesses the highest number of chromosomes known within the genus. Populations of E. yavapaiensis occur in central Arizona between 1025 and 1860 m elevation and are associated with volcanic bedrock. Fifty three percent of the individuals studied pr...

First-time meiotic chromosome determinations were made for some South American Cactaceae: Armatocereus godingianus (2n = 22), Cleistocactus leonensis (2n = 22), C. sepium var. morleyanus (2n = 22), C. sepium var. sepium (2n = 22), C. sepium var. ventimigliae (2n = 22), Opuntia xaequatorialis (2n = 66), O. bakeri (2n = 99), O. pubescens (2n = 44), O...

Documented meiotic and mitotic chromosome numbers are reported For 91 taxa, including intergeneric and interspecific hybrids, representing 15 genera of Cactaceae from southwestern United States and northern Mexico. Chromosome counts are reported for the first time for 32 taxa and additional ploidy levels for five taxa. These chromosomes counts are...

A total of 72 meiotic chromosome numbers were determined for 58 taxa representing 23 genera of Acanthaceae from the United States, Mexico, Panama, and Peru. Chromosome numbers of 41 of these taxa are reported for the first time. Chromosome numbers obtained in Aphanosperma (n = 18), Chalarothyrsus (n = 18), Gypsacanthus (n = 18), Ixtlania (n = 14),...

A morphometric analysis ofOpuntia spinosior, O. fulgida, and their putative hybrid,O. × kelvinensis was supplemented with cytogenetic data and pollen stainability for all OTUs. The morphometric analysis supported the hypothesis for the hybrid origin ofO.×kelvinensis and indicated that limited backcrossing has occurred betweenO.×kelvinensis andO. sp...

Documented meiotic and mitotic chromosome numbers and behavior are reported for 62 taxa representing 11 genera of Cactaceae from the southwestern United States and northern Mexico. Chromosome numbers for 12 species and six natural interspecific hybrids are first counts. New numbers were determined for four additional species. Chromosome counts of d...

Putative hybridization between Opuntia fulgida Engelm. and O. spinosior (Engelm.) Tourney (Cactaceae, subgenus Cylindropuntia, section Cylindropuntia) was investigated using morphometrics, cytology, pollen stainability, chemistry and embryology. That O. spinosior is a sexually normal species was supported by its normal megasporogenesis, megagametog...

The attributes of an ethanol bath method of preparing cacti and other stem succulents for mounting on standard herbarium sheets are compared to a microwave method.

Meiotic chromosome numbers are reported for 30 taxa representing 12 genera of Acanthaceae from Mexico and the southwestern United States. Chromosome numbers of 25 of these taxa are reported for the first time. Chromosome numbers obtained in Henrya (n = 18), Holographis (n = 13, 26, 39), Mexacanthus (n = 18), Mirandea (n = 18), and Stenandrium (n =...

The putative intergeneric hybridization between Stansbury CUffrose (Cowania) and Apache Plume {Fallugia) is found to be undocumented. Chromosome counts support reported base numbers for Cowania and FaUtigia to be n = 9 and n = 14 respectively. In 1975, Blauer et al. reported the exis-tence of a small population of putative hy-brids between Stansbur...

Ethnobotany of the Yurok, Tolowa, and Karok Indians of northwest California, including original ethnographic data obtained from individuals of these cultures. The uses of vascular and non-vascular plants by these peoples are discussed, as well as signicance of their plant names with respect to folk taxonomy.

Thesis (M.A.)--Humboldt State University, 1981. Includes bibliographical references (leaves [134]-141). Typescript (photocopy).

Individuals of E. sneedii var. sneedii were found to occur in greater abundance within the Guadalupe Mountains than was previously recorded. No additional populations morphologically intermediate between E. guadalupensis and E. sneedii were found. Taxonomic affiliation and geographic distribution among three Escobaria taxa were readdressed with phe...

A biosystematic study is underway primarily to ascertain the taxonomic validity of E. horizonthalonius var. nicholii, which is listed as endangered by the USFWS. The present taxonomic status of the variety is tenuous and there is marked disagreement among authors of classical taxonomic treatments. In order to test the hypothesis that individuals of...