Boraginaceae tribe Trigonotideae comprises a heterogenous assemblage of taxa, many of which have been shown to belong to widely divergent lineages in Boraginaceae in the recent past, with some taxa now assigned to three of the four currently recognized tribes of the Boraginaceae s. s., namely the Cynoglosseae, Echiochileae, and Lithospermeae. The systematics of Moritzia and Thaumatocaryon, the only endemic South American genera of Boraginaceae, have been controversially discussed in the past, and their most recent placement was in Trigonotideae. The present study investigates the phylogenetic relationships of “Trigonotideae” based on micromorphology and molecular data (ITS including 5.8S rRNA, and the trnL-trnF spacer). Molecular data show that “Trigonotideae” are polyphyletic, and none of its members is at all closely related to Trigonotis itself. Moritzia and Thaumatocaryon are closely allied to each other and are the sister group of the Old World Boragineae. Flowers, pollen, and fruit morphology strongly support this systematic placement. Extant (native) Boragineae are absent from North America and had not previously been reported from South America, whereas members of the Cynoglosseae, Echiochileae, and Lithospermeae have been reported from both continents. Moritzia and Thaumatocaryon are thus the only native representatives of Boragineae in the Americas and represent an unexpected western Eurasian/South American disjunction. However, several (widespread and abundant) fossil taxa from the Cenozoic of North America (especially species of †Prolithospermum) can be confidently placed into Boragineae. Extant Moritzia /Thaumatocaryon likely go back to a lineage which reached North America from Europe and then migrated into South America, with subsequent extinction in North America.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.