| Abstract Detail
Systematics Kephart, Susan [1]. Disentangling species in dynamic landscapes: Do unusual ecological contexts matter in shaping morphology, pollination, and genetic variation in Camassia? Species divergence is often inextricably linked to how populations respond in diverse environments, whether change is triggered by abiotic habitat stressors, or interactions with pollinators, herbivores, and seed dispersers. Resolving species boundaries in such dynamic landscapes is particularly difficult to disentangle in new or rapidly diverging lineages. Perennial, spring-flowering geophytes of Camassia (camas, wild hyacinths; Asparagaceae) are part of a diverse radiation of agaves and yuccas (Agavoideae) whose cells show bimodal, karyotypic size classes. Within the ~41 myr history of this ABK clade, previous molecular analyses imply Camassia and Chlorogalum (soap root) are relatively young lineages (10.7 myr). In Camassia, the six morphologically variable species, together with 10 named subspecies, comprise a taxonomically difficult, yet tractably sized complex of taxa that often grow in temporally challenging environments. Plants require cool, often wet conditions in early spring whether in seeps, riparian corridors, or wet meadows and forest glades. By mid-summer, these habitats can be hot and dry, with fruiting plants persisting via bulbs in rocky crevices. Morphological and genetic studies provide some resolution of taxa, but the relationship of these data to biotic and abiotic factors is still little understood. Here we share new data that support unusual, range disjunctions for the two rarest of the four western species, C. howellii and C. cusickii. We also ask to what extent differing edaphic, geological, and elevational conditions might shape their genetic differentiation, floral development, and pollination modes relative to their wider-ranging congeners in both ancestral and later derived clades. Such data can lend valuable insights into early stages of speciation, as well as improve keys, and resolve difficult circumscription of allopatric and sympatric taxa, some of which undergo hybridization.
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1 - Department Of Biology, Salem, OR, 97301, United States
Keywords:
Camassia
Agavoideae
ecological
edaphic
Floral traits
morphological variation
pollinator
range expansion
species delimitation
Speciation
sympatry.
Presentation Type: Oral Paper
Session: 3, Systematics I--Tracheophytes, Pteridophytes to Monocots 1
Location: 110/Mayo Civic Center
Date: Monday, July 23rd, 2018
Time: 10:30 AM
Number: 3010
Abstract ID:965
Candidate for Awards:None |
