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Wilfrid Laurier University Leaf
October 25, 2016
Canadian Excellence



Mihai Costea

We are on the cover of American Journal of Botany!

Sep 1/09

Our paper received full cover in the American Journal of Botany, September 2009 issue:

Costea, M. and S. Stefanović. 2009. Cuscuta jepsonii (Convolvulaceae), an invasive  weed or an extinct endemic? American Journal of Botany 96: 1744-1750.

Cover Illustration: Cuscuta (dodders) species are obligate parasitic plants with stems that resemble yellow-orange spaghetti. Their seedlings can detect and select among potential hosts using volatile chemical cues. Dodders can transfer viruses, mycoplasmas, and macromolecules from one host to another, and they are involved in the translocation of mRNA from their hosts and in horizontal gene transfer spanning deep phylogenetic distances. Similar to other parasitic plants, Cuscuta spp. have been described as keystone species and as “ecosystem engineers” because they promote and maintain the biodiversity of plant communities in which they occur. Even though only ca. 15 species worldwide of the 180–200 species in the genus Cuscuta are serious agricultural pests, the entire genus is often posted on governmental lists of noxious/invasive or quarantine weeds. In reality, however, at least 50% of the Cuscuta species are of major conservation concern. Cuscuta jepsonii, endemic to California, is a prime example; it might be considered an invasive weed, when in fact the species may be extinct.

The composite cover image is part of an unpublished art project called Imaginary Flowers, an exploration of symmetry and beauty in flowers. The original image source is the corolla of C. jepsonii (see photograph below), of which only 5–10 flowers exist in various herbaria. The final image resulted from the z-stacking of 12 photographs of the corolla taken from successive optical planes with a Nikon SMZ1500 stereomicroscope equipped with a PaxCam Arc digital camera. For more details on the technique, see the Digital Atlas of Cuscuta ( The symmetry alterations drawn in red (below) were rendered mostly with the programs Kaleider and Liquib by J. Holcomb ( M. Costea will soon launch the Imaginary Flowers project at See Costea and Stefanovic—Cuscuta jepsonii (Convolvulaceae): An invasive weed or an extinct endemic? on pp. 1744–1750 in this issue. Image credit: Mihai Costea.”

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