Perennial pepperweed (Lepidium latifolium) is a potential threat to biodiversity and ecosystem function in the communities that it invades. The mechanism for its successful invasion of riparian and wetland environments includes reproduction via seed and root propagules and its ability to withstand long duration flooding and saline conditions once established. Controlling this species presents a number of challenges for land managers, including difficult property access, limited herbicide choice, and the varied success of weed control measures. In this study, we tested the efficacy of a nonchemical-modified tarp treatment, and compared posttreatment stem counts to herbicide treatments with Mow–glyphosate and chlorsulfuron in a wildland setting. We found that tarping applied in combination with a mow and till treatment was effective at controlling perennial pepperweed at levels similar to herbicide treatments with Mow–glyphosate and with Mow–chlorsulfuron. However, Mow–Till–Tarp treatment is extremely time consuming and has the potential to limit native plant community recovery.

Lepidium latifolium L. (Brassicaceae) grows successfully in a high-altitude cold arid environment. Little molecular data are available for this plant despite its immense ecological importance as a cold- and drought-adapted species. We used a novel approach to identify microsatellite regions using genome walker libraries, called as Random Scans at Microsatellite Regions (RaSMiR), and implemented them on genotypes collected from relatively different topographical conditions within a small geographical area. The success rate of finding a microsatellite sequence using this methodology was 100%, and on developing the RaSMiR technique itself as a molecular marker, 230 electrophoretic bands were obtained using 13 different RaSMiR primers in combination with a microsatellite sequence primer. On an average, 17 bands were obtained for each primer. The electrophoretic profiles generated by RaSMiR markers were distinct from those produced by inter-simple sequence repeat markers. This information has been documented as a dominant marker data, and has been used to construct a neighbour-joining tree that successfully distinguished all genotypes. RaSMiR is an attractive approach for the development of unique and informative microsatellites, or for genome scanning directly as a molecular marker that can potentially be employed for the estimation of genetic diversity or to identify polymorphic loci involved in adaptations particularly in the non-model species, for which sufficient genomic data are not available.