Witchweed, [Striga asiatica (L.) Kuntze5 STRLU], an important parasitic weed throughout much of the old world, occurs as a recent (30 yr) introduction in a limited region in North and South Carolina. Reproduction in this population has been shown to occur primarily through self-pollination of flowers. Genetic diversity in two populations from this region was assessed, utilizing starch gel electrophoresis and staining of enzymes. An average of 64 individuals was observed to be monomorphic at an estimated minimum of 32 genetic loci coding 18 enzyme systems. This lack of polymorphism is attributable to the probable founding of the population by one or a few individuals coupled with the predominantly autogamous breeding system.

Toadflax invasion into natural areas has prompted interest in weed management via biological control. The most promising biological control agent currently available for the control of Dalmatian toadflax is Mecinus janthinus, a stem-boring weevil that has been shown to significantly reduce toadflax populations. Some land managers, however, are reluctant to release approved weed biological control agents based on concerns about possible nontarget impacts. Few postrelease examinations of biocontrol impact and host specificity have been performed, despite the call for such information. This study examined the host specificity of Mecinus janthinus, postrelease, in relation to Colorado sites to provide information to managers about its relative safety as a weed biological control agent. This study employed three components: (1) greenhouse choice and no-choice experiments; (2) no-choice caged field experiments; and (3) release-site evaluation of nontarget use of native plant species where this weevil has been released and has established. Both greenhouse and field experiments failed to demonstrate nontarget use of native plant species by M. janthinus in the region where it was studied, even in no-choice starvation tests. We found no evidence of nontarget herbivory on native plants growing at toadflax sites where M. janthinus was well established. These results support the continued use of M. janthinus as a low-risk biological control agent for the management of toadflax in the Rocky Mountain Front Range.

Pedicularis ser. Tenuirostres Maxim. (Orobanchaceae) is demonstrated to be the correct name for the group usually referred to as P. ser. Pectinatae Prain. The series is here revised and 12 species are accepted. Its species are centred in the NW Himalaya, particularly Pakistan where there is much local infraspecific variation. Two species are excluded from the series: Pedicularis rhynchotricha P.C.Tsoong from China (Xizang) is placed in P. ser. Rhynchotrichae R.R.Mill and P. birmanica Bonati is confirmed as a member of P. ser. Brevifoliae (Prain) Bonati. One new species of Pedicularis ser. Tenuirostres is described: P. yamazakiana R.R.Mill from Nepal, which was formerly confused with P. pectinata subsp. palans Prain. Pedicularis jainii Aswal & Mehrotra is demonstrated to be a superfluous name for P. pyramidata Royle ex Benth. Pedicularis kashmiriana var. ornata Pennell is considered to be indistinguishable from P. pyramidata although P. kashmiriana var. kashmiriana is a recognisable taxon. An IUCN conservation assessment is proposed for Pedicularis rhynchotricha and for each taxon within P. ser. Tenuirostres.

Pedicularis L. series Curvipes (Prain) Hurus. (=Pedicularis [unranked] Curvipes Prain) in the Orobanchaceae (often included in the Scrophulariaceae s.l.) is revised. It is demonstrated that the correct name for the series is Pedicularis ser. Curvipes, not Pedicularis ser. Curvipedes as used by at least two previous authors. Arguments are presented for the retention of the three existing species, Pedicularis curvipes Prain, Pedicularis nagaensis H.L.Li and Pedicularis amplicollis T.Yamaz., and the taxonomic history of each is summarized. Pedicularis curvipes from Sikkim and Pedicularis nagaensis from NE India are very similar but can be distinguished on corolla and seed characters. Flowering material of Pedicularis curvipes collected from cultivated material of uncertain origin in 1900 is positively identified as that species for the first time. The known geographical range of Pedicularis nagaensis, which was previously believed to be endemic to a restricted area of Nagaland in NE India, is extended to include Manipur. Pedicularis amplicollis from Bhutan is distinct from both the other two and easily separable by its woolly, 4-lobed calyx. A key to the series and formal taxonomic accounts of each species are provided. The relationships of the series with related series, particularly Pedicularis ser. Furfuraceae, are discussed.

The genus Campylanthus (Scrophulariaceae) is revised and 15 species are recognized. The genus shows a markedly disjunct pattern of distribution, with two species in Macaronesia, 12 in northeastern Africa and Arabia, and one in western Pakistan. With few exceptions all have very restricted distributions. The position of the genus within the Scrophulariaceae is discussed, and it is concluded that Campylanthus is best placed as incertae sedis. Morphological aspects of the genus are discussed and a cladistic analysis including all species is presented. The analysis indicates a basal split between western and eastern species in the genus. A key, descriptions and distribution maps for all species are provided, and some lectotypes and neotypes are selected.

Investigations were conducted in six farm fields (1.5 to 3 ha each) in Burkina Faso with objectives to (1) study adult Smicronyx spp. (Coleoptera: Curculionidae) population dynamics during Striga hermonthica (Scrophulariaceae) seed-pod production, (2) assess the impact of different population levels of Smicronyx spp. on St. hermonthica capsule production and, (3) estimate Smicronyx female reproductive success in seed-pod galls. A Univac portable sampler was used to sample adult Smicronyx spp. and St. hermonthica densities were assessed using aim2 metal quadrat. Fifty St. hermonthica shoots per field were sampled each week. Before the emergence of St. hermonthica, Smicronyx adults were found on nearby Striga éspera (Willd) Benth. fields. Striga hermonthica shoots produced on average ca. 24 seed capsules each, while each female Smicronyx galled from 12 to 32 seed pods. Seed-pod galling alone was not sufficiently high to be considered as a successful reduction factor for St. hermonthica seed production in natural conditions. Smicronyx spp. adult population levels decreased during the St. hermonthica capsule production period. Increased population levels of Smicronyx spp. resulted in higher percentages of St. hermonthica seed-pod galls, suggesting that a ugmentative techniques, if used as part of an integrated control programme could be a worthwhile strategy.