Plant Systematics at
 
 
San Diego State University
Research



Next Generation Sequencing Information


Current and Past Research Projects

Systematics of Oreocarya [Cryptantha s.l., in part] (Boraginaceae)

Oreocarya is a recently resurrected genus of approximately 60 (-67) species, distributed in western North America.
Lee Ripma is conducting a phylogenetic analysis of species in the genus, using ITS nrDNA, chloroplast DNA, and morphological features. Lee will be looking at character evolution with respect to edaphic habitat, nutlet morphology, and aspects of reproductive biology, such as heterostyly.

Systematics of Fritillaria (Liliaceae)

Fritillaria is a genus of approximately 130 species, distributed in western North America and from western Europe to eastern Asia. Sean Ryan is conducting a phylogenetic analysis of the 22 western North American species, using ITS nrDNA, chloroplast DNA, and morphological features. Sean will be correlating phylogeny with morphology and reproductive biology, specifically the chemical composition of floral scent compounds.

Systematics of Cryptantha s.l. (Boraginaceae)

The genus Cryptantha s.l. consists of approximately 200 species, distributed in western North and South America. The fruits, consisting of one to four tiny nutlets, have a tremendous variety of shape and sculpturing features, largely used in delimiting taxa. (See Cryptantha Taxonomy & Images web page.) Kristen Hasenstab conducted a phylogenetic analysis of the species of this complex, using ITS nrDNA, chloroplast DNA, and morphological characters for her M.S. thesis (pdf). In a recent publication, "Cat’s Eyes and Popcorn Flowers: Phylogenetic Systematics of the Genus Cryptantha s.l. (Boraginaceae)" (Systematic Botany, in press), we have split the genus Cryptantha s.l. into 5 genera: Cryptantha s.s., Eremocarya, Greeneocharis, Johnstonella, and Oreocarya.

Systematics of Cryptantha s.s. (Boraginaceae)

The genus Cryptantha s.s. consists of approximately 123 species, distributed in western North and South America. Makenzie Mabry will be refining a phylogenetic analysis of the species of this complex, using Next Generation sequencing techniques for her M.S. thesis. She will be sampling many new species and is hoping to get much better support values for clades. The resultant cladogram(s) will allow her to assess more critically character evolution, the history of biogeography, and timing of evolutionary divergence.

Systematics and Taxonomy of Chenopodium (Chenopodiaceae)

Nuri Benet-Pierce has been working intensively on various taxonomic problems in the genus Chenopodium, the "goosefoots." Her work resulted in the discovery of a new species in California, Chenopodium littoreum Benet-Pierce & M. G. Simpson. Madroño 57: 64-72. 2010 (pdf). Nuri is co-author of the Chenopodium and Dysphania treatments for
The Jepson Manual 2.

Systematics of Calyptridium (Portulacaceae)

Calyptridium is a genus of 8 species, distributed in western North America and northern Mexico. Our lab conducted a morphometric study of the Carlyptridium parryi complex: Madroño 57: 145-160 (pdf). Matt Guilliams completed a phylogenetic analysis of the complex, using ITS nrDNA, chloroplast DNA, and morphological features for his M.S. thesis (pdf).

Systematics of Pogogyne (Lamiaceae)

Pogogyne is a genus of 8 species, occurring in California, Oregon, and northern Baja California. Michael Silveira completed a phylogenetic relationships of the species for his M.S. thesis (pdf).

Anatomy of the Haemodoraceae and its Systematic Significance

The Haemodoraceae is a family of monocotyledons that contains 14 genera and about 100 species. This study, conducted by Layla Aerne (M.S., May 2007), investigated the vegetative anatomy of the family (see pdf). The descriptive work of this research is to be published in the Kew Monocot Anatomy series (Aerne & Simpson, in prep.). A comprehensive phylogenetic analysis of the family was conducted using these new data, along with re-interpreted morphological data and existing molecular data. This analysis has given further elucidation regarding the classification and character evolution in the Haemodoraceae.