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Lennoaceae are a small family of root parasites endemic to Mexico and the southwestern United States. These plants are non-photosynthetic and exhibit a reduction of morphological features which makes systematic placement difficult. Earlier studies of Lennoaceae based on floral and pollen morphology have suggested relationships with Boraginaceae, 'Hydrophyllaceae,' or Verbenaceae. Molecular evidence is presented from all three genomic compartments to test these hypotheses. The plastid gene rps2, the mitochondrial genes cox 1 and atpA and the nuclear ITS region were sequenced and subjected to phylogenetic analysis. Preliminary results indicate that a monophyletic Lennoaceae is most closely related to Ehretioideae, a subfamily of Boraginaceae. This subfamily contains host plants of Lennoaceae, indicating a possible case of adelphoparasitism, the first such association suspected among the angiosperms. Further investigation should resolve this question and determine the closest extant relative of Lennoaceae among this group.

DNA sequence data from the low-copy nuclear gene alcohol dehydrogenase (Adh) were used to test the putative hybrid origin of several diploid and tetraploid species of peonies belonging to Paeonia section Paeonia (Paeoniaceae). Two paralogous loci (Adh1 and Adh2), duplicated prior to the diversification of Paeonia species, were amplified with locus-specific primers and cloned for one or more accessions from each species. All distinct clone copies were included in a single simultaneous parsimony search for each locus. Adh1 and Adh2 support that several tetraploid species, including the 'arietina' species group (P. arietina, P. humilis, P. officinalis, P. parnassica), P. peregrina, and P. banatica, are of allopolyploid origin. After the initial hybridization event, tetraploid peonies may have gone on to speciate and further hybridize, creating new species such as P. officinalis. For putative hybrid diploids, distinct sequences were found at the Adh2 locus for P. emodii, and Adh1 sequence polymorphism was detected for P. japonica and P. obovata. This may imply that heterozygosity resulting from hybridization can be maintained at a nuclear locus but homogenized at the other following genome rearrangement in a diploid hybrid. Overall, Adh2 corroborates many of the findings based on Adh1; however, the tempo of gene duplication and deletion at that locus is much more dynamic than Adh1, with many pseudogenes found in several species.

Hydrophyllaceae (Asteridae: Boraginales) are a diverse group of herbs and shrubs with a worldwide distribution. There are 17 genera and ca. 300 species currently assigned to the family. Despite the fact that these species are included within the same taxonomic unit, it has been observed that the family is an assemblage of 'morphological and geographical odds and ends' held together by shared floral and fruit characters. Many of the floral and fruit traits may be symplesiomorphic upon further evaluation in a phylogenetic context. Two independent DNA sequence data sets will be utilized to address the following issues: (1) are Hydrophyllaceae monophyletic and what morphological and distributional data support the results, (2) what are the closest relatives to Hydrophyllaceae, and (3) what are the intergeneric relationships? In total, 53 ndhF and 49 ITS sequences will be included, representing 16 of the 17 Hydrophyllaceous genera, as well as a broad sampling of outgroups in Boraginaceae. A preliminary assessment of the two data sets suggests that they are congruent and results will be presented for the combination of the data. Hydrophyllaceae, excluding Hydrolea and Codon, are monophyletic. The 'core' Hydrophyllaceae are sister group to the 'ehretioid' Boraginaceae. There are two clades within Hydrophyllaceae: an entirely herbaceous clade including Phacelia, the tribe Hydrophyllaceae, and allied genera Hesperochiron, Tricardia, Romanzoffia, and Emmenanthe, and a clade containing Nama and the woody genera Eriodictyon, Turricula, and Wigandia. The 'core' Hydrophyllaceae are an entirely New World clade. Although floral characters are symplesiomorphic and not indicative of relationships, the fruit characters - capsules, parietal placentation, and many seeds per fruit - are synapomorphies that differentiate the family from Boraginaceae s.l.