XVI International Botanical Congess

Lachnocaulon is composed of seven herbaceous species found in the southeastern United States and Cuba. It is distinguished from the remaining Eriocaulaceae by monothecate anthers and extremely reduced petals, and traditionally has been considered most closely related to Tonina, an aquatic genus that ranges from southern Mexico into South America. However, it has been proposed that Lachnocaulon and Blastocaulon, a small genus restricted to South America, are more closely related. To examine the generic affinities of Lachnocaulon, we have sequenced the trn L/trn F intergenic spacer of the chloroplast genome. The data support the monophyly of Lachnocaulon and a sister group relationship with Tonina, while the placement of Blastocaulon remains unresolved. We are sequencing additional Eriocaulaceae genera to determine the placement of Blastocaulon in relation to Lachnocaulon.