WEESE, TERRI L.* AND LEIGH A. JOHNSON. Department of Botany, North Carolina State University, Raleigh, NC 27695 and Department of Botany and Range Science, Brigham Young University, Provo, UT 84602. - Taxonomic limits and phylogenetic affinities of Saltugilia: molecular and morphological support for generic recognition apart from Gilia.
Saltugilia first received formal taxonomic status in 1954 as a
section of Gilia, and initially included five species in two
species groups: Gilia splendens, G. caruifolia, and G.
australis, and G. leptalea and G. capillaris. The
latter two species were subsequently removed to their own section of
Gilia before ultimately being removed from the genus. Gilia
stellata andG. scopulorum were included in section
Saltugilia in 1959, and a sixth species, G. yorkii, was
added in 1999. Previous analyses of nuclear ITS and chloroplast
matK DNA sequences suggest Gilia splendens, G.
caruifolia, and G. australis form a lineage independent of
the true gilias. Additional DNA analyses and morphological
characterization concur, providing support for elevating
Saltugilia to generic status. As here circumscribed,
Saltugilia includes S. splendens, S. caruifolia, S.
australis, and an unnamed species. Gilia stellata, G.
scopulorum, and G. yorkii are retained in Gilia.
Saltugilia is characterized morphologically by a verrucate seed
coat and combination of chainlike trichomes on the leaves and short,
flat-topped, multicellular glands in the inflorescence. Comprising an
apparent incipient species complex, the four species within
Saltugilia are distinguished primarily by floral features and
distribution. They show little molecular differentiation in the loci
we sampled. Two chloroplast haplotypes are distinguished, but these
do not entirely reflect taxonomic or geographic boundaries.
Key words: classification, Gilia, phylogeny, Polemoniaceae, Saltugilia