Chemical profiles of ovular secretions of ambophilous gymnosperms show a clear signal of pollinator-driven selection, including higher levels of carbohydrates than anemophilous taxa, lower levels of amino acids, and the presence of specific amino acids, such as β-alanine, that are known to influence insect feeding behaviour and physiology.

The bile pigment bilirubin-IXalpha is the degradative product of heme, distributed among mammals and some other vertebrates. It can be recognized as the pigment responsible for the yellow color of jaundice and healing bruises. In this paper we present the first example of the isolation of bilirubin in plants. The compound was isolated from the brilliant orange-colored arils of Strelitzia nicolai, the white bird of paradise tree, and characterized by HPLC-ESMS, UV-visible, (1)H NMR, and (13)C NMR spectroscopy, as well as comparison with an authentic standard. This discovery indicates that plant cyclic tetrapyrroles may undergo degradation by a previously unknown pathway. Preliminary analyses of related plants, including S. reginae, the bird of paradise, also revealed bilirubin in the arils and flowers, indicating that the occurrence of bilirubin is not limited to a single species or tissue type.

Evolutionary trends and phylogenetic relationships in the Strelitziaceae (Zingiberales) were investigated using sequence data from ten plastid and two nuclear regions and a morphological dataset. The status of species of Strelitzia were evaluated in terms of the phylogenetic species concept. Relationships among the genera remain equivocal with two hypotheses emerging: (i) Strelitzia sister to a clade comprising Raivnala and Phenakospermum when indels are included, or (ii) Ravenala sister to the remainder of the Strelitziaceae when indels are excluded in/from the combined molecular and 'total evidence' analyses. Within Strelitzia, S. nicolai is sister to the rest of the genus, with S. alba sister to S. caudata. Strelitzia regirme is shown to be paraphyletic as S. júncea is nested within it, but more sampling at the population level is needed to confirm the taxonomic status of S. júncea. The highly localized and endangered Strelitzia alba is confirmed as a distinct species, as are S. caudata and S. nicolai, despite few morphological differences. Evolutionary trends are linked to changes in habitat and coevolution with pollinators. Climate change in southern Africa is thought to have restricted Strelitzia nicolai (or its ancestor) to the eastern coastal region, with subsequent allopatric speciatíon of S. alba and S. caudata, and relatively recent parapatric divergence of S. júncea from S. reginae. SYSTEMATIC BOTANY [Volume 37 MATERIALS AND METHODSTaxon Sampling-All seven currently recognized species comprising the three genera of the Strelitziaceae and two outgroup species, Orchidantha fimbriata and O. siamensis, were included in this study. Orchidantha N. E. Br., the single genus in the Lowiaceae (Lane 1955;Johansen 2005), was selected as the outgroup based on previous phylogenetic analyses. Lowiaceae has repeatedly been recovered as sister to the Strelitziaceae (Chase et al 2000; Solfis et al. 2000;Kress et al. 2001;Givnish et al. 2006;Soltis et al. 2007), with one exception where Lowiaceae was placed sister to remaining families of the Zingiberales, with Strelitziaceae comprising the next clade-diverging (Johansen 2005). Multiple exemplars (two individuals per species) were used for all Strelitzia species to test for monophyly. Appendix 1 lists the specimens with accession numbers and vouchers.Molecular Characters-Rapidly evolving intron and intergenic spacers were selected from ten plasfid regions, viz. matK -5'trnK, psbA-matK, psbB-psbH, Ycf6-trnC, rpL16 intron, rpoB-trnC, trnS-trnfM, triiY-trnE (Shaw et al. 2005), rpL32-trnt (Shaw et al. 2007), rpS16 (Levin et al. 2004), and two nuclear regions: the external transcribed spacer (ETS) region of ribosomal DNA and rpb2, the second intron of the second subunit of RNA polymerase II. A single accession for each member of the Strelitziaceae was sequenced for all ten plastid regions, and a second accession sequenced for three plastid regions, matK -5'trnK, rpS16 and the rpL16 intron (with the exception of R. madagascariensis and S. alba for the rpL16 intron), and the ...

Strelitzia reginae Aiton is an iconic plant known for its vibrant orange and blue inflorescences. Floral pigments include carotenoids and the anthocyanin delphinidin-3-rutinoside. S. reginae has black seeds with vivid orange arils, yet the basis for the orange color is unknown. We recently discovered bilirubin in the arils of S. nicolai. Previously, this pigment was known only to exist in animals as a breakdown product of heme. Using high-performance liquid chromatography (HPLC) and HPLC/electrospray ionization–tandem mass spectrometry, we now show that bilirubin is the primary aril pigment of S. reginae and is also present in low concentrations in its sepals (less than 44.0 ng·g−1).