Systematics and Conservation of the Genus <em>Malacothamnus </em>(Malvaceae)

<p>Malacothamnus (Malvaceae) is a genus of fire-following shrubs found primarily in the California Floristic Province. The taxonomy of the genus has been controversial for many years due to conflicting treatments, which recognize between 11 and 28 taxa. Many taxa of conservation concern are not recognized in some of these treatments, which makes resolving taxonomic questions in the genus a conservation priority. To resolve these questions, I use a combination of morphological, geographic, and phylogenetic evidence. Morphological measurements of specimens were first analyzed with principle component analysis (PCA), pairwise permutational multivariate analysis of variance (PERMANOVA), and linear discriminant analysis (LDA) to answer (1) whether taxa relegated to synonymy by some authors are morphologically distinct or not, (2) whether there is morphological evidence to support purported intergradation between taxa, (3) whether previously defined morphological boundaries between taxa are justifiable or need refining, and (4) whether populations of hypothesized novel taxa are morphologically distinct from the taxa they have been included within. Thirty-eight morphological groups with varying levels of distinctness were recovered and used as hypothesized lineages to be tested in a phylogenetic framework using a restriction site-associated DNA sequencing (RADseq) dataset. Samples were analyzed using maximum likelihood analysis, quartets-based species tree analysis, neighbor-net analysis, and multidimensional scaling. Based on the totality of evidence, a new treatment of the genus is proposed recognizing 30 taxa in 22 species. This treatment includes life history, discussion and illustrations of morphological characters useful in identification, and conservation information relevant to the genus. A key to all taxa is presented, followed by morphological descriptions, synonymy, common names, typifications, distribution maps, phenology, conservation status, notes, and photographs.</p>

Name thesis:degree_name

Botany, PhD

Level thesis:degree_level

Restricted to Claremont Colleges Dissertation

Discipline thesis:degree_discipline

Botany

Year dc:date.available

2022

Author dc:creator

• Morse, Keir

Contributors dc:contributor

• J.Travis Columbus
• Naomi Fraga

• Botany

Repository record dc:identifier

https://scholarship.claremont.edu/cgu_etd/484

OAI identifier oai:identifier

oai:scholarship.claremont.edu:cgu_etd-1515