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Abstract Detail

Systematics Section/ASPT

Riggs, Erin [1], WILSON , CAROL A [2].

Phylogenetic relationships among the Iris hartwegii complex re-examined using cpDNA and nDNA sequence data and morphology. Erin L. Riggs1 and Carol A. Wilson2.

Iris series Californicae is a clade of about 18 taxa that are generally distributed in foothill habitats from Washington to California.  In the Sierras and southern California transverse ranges the Iris hartwegii complex, as currently circumscribed, comprises four subspecies: I. h. subsp. columbiana, I. h. subsp. hartwegii, I. h. subsp. australis, and I. h. subsp. pinetorum.  Previous studies using morphology, RAPDs and rnDNA (ITS) data have not fully clarified relationships among taxa.  This investigation re-examines relationships using ten populations representing the geographic distribution of the species complex and five plastid and low-copy nuclear markers, some of which were developed based on plastid genome and RNA sequencing.  Surprisingly, resolution of trees resulting from the plastid marker dataset is more complete than trees resulting from low-copy nuclear data even though the numbers of bp for the datasets were similar.  Results indicate that I. h. subsp. pinetorum is distinct from other species in the complex and should be recognized at the species level.  It has been suggested that this taxon originated as a hybrid between subsp. hartwegii and I. tenuissima, a hypothesis that is neither supported nor refuted with our data.  Populations of the allopatric I. h. subsp. australis are monophyletic and we concur with the current recognition of this taxon at the subspecific rank.  The four populations of the relatively widespread I. h. subsp. hartwegii and the two know populations of the rare I. h. subsp. columbiana are paraphyletic and can be interpreted as forming one clade with three subclades or three clades.  We discuss our taxonomic conclusions for the species complex in the context of the morphology and biogeographical distributions of these California taxa.    

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1 - Leach Botanical Garden, Botany, 6704 SE 122nd Ave , Portland, OR, 97236, United States
2 - Rancho Santa Ana Botanic Garden, Claremont Graduate University, Claremont, CA, 91711


Presentation Type: Oral Paper:Papers for Sections
Session: 31
Location: Pines South/Boise Centre
Date: Tuesday, July 29th, 2014
Time: 4:00 PM
Number: 31009
Abstract ID:848
Candidate for Awards:None

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