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Eremophila is an Australian genus of 212 species ranging from prostrate shrubs to small trees, the great majority of which occur in Western Australia. Recent interest in the genus's germination strategies developed out of a need to seek rehabilitation techniques for mine-site and rangeland areas. The genus is of special interest because of its broad geographic range and prominence in vegetation associations of the arid zone, especially in Western Australia, where it often dominates or codominates over wide areas. Many Eremophila species are known to be tolerant of drought, fire, frost, grazing, and salinity, and would be very suitable for revegetation programmes; however, the genus germinates poorly, for reasons that are not fully understood. During the early 1980s attempts were made, with limited success, to rehabilitate open-cut mine-site waste dumps at Mt. Newman using broadcast seed and rooted cuttings and transplanted seedlings at the Pilbara mine venture at Paraburdoo. Tissue culture and grafting have also been attempted, but environmental management acknowledges that the broadcast seed method is the only cost-effective means of mine-site rehabilitation. Under field conditions the germination of Eremophila occurs in response to heavy rain in autumn and winter, especially with milder temperatures; however, up until now the use of Eremophila in rehabilitation practices has been limited because of the high percentage of seeds that fail to germinate. Two causes for this have been postulated. First, the environmental conditions may not be appropriate for germination. Physical dormancy resulting from the hard woody fruits may be overcome by using a scarification pre-treatment. Second, seed may still fail to germinate even though favourable conditions exist; a secondary chemical mechanism in the form of inhibitors associated with the fruit wall is hypothesised. Chemical properties of the seed, seed coat, or fruit may regulate germination until the fruit wall has been effectively worn away and the chemicals leached out. Few experimental procedures have been carried out to verify these hypotheses, and few studies have examined either fruit productivity (seeds per fruit) or seed viability. Eremophila fruit are dry with a papery exocarp or drupaceous with a fleshy or succulent mesocarp and a woody or crustaceous endocarp and contain between 2 and 12 seeds. Seed viability in E. maculata ranges from 74% to 92% in the first 3 years after fruit maturity, decreasing markedly to 8% after 13 years. Similar patterns have been recorded for E. goodwinii. Effective environmental management utilising Eremophila may be approached in three ways. First, scarify fruit to promote the uptake of water and oxygen; second, use fruit between 1 and 5 years to ensure the highest viability rating; and third, collect fruit from healthy shrubs showing no evidence of insect or fungal attack to ensure quality of fruit. Further research on the genus should include ecological studies, currently poorly understood, and edaphic and soil amelioration projects (e.g., on post mine-site tailings) in an attempt to optimise the vegetation potential of Eremophila., II. Introduction Previous studies on Eremophila have focused on the taxonomy (Chinnock, 1981a, 1982b, 1983, 1986a; Dell, 1975a), biochemistry (Jefferies et al., 1961, Jefferies & Knox, 1961; Dell, 1975b; Ghisalberti [...]

The monotypic genus Bontia, endemic to the Caribbean, is the extreme outlier of a primarily southern-hemisphere Old World family, the Myoporaceae. Ninety-five percent of the 250 species of Myoporaceae sensu R. J. Chinnock (in press) are endemic to Australia. Only six species in the family occur north of the equator; of these, all but Bontia daphnoides are locally distributed in the western Pacific. Is the evolutionary history of Bontia truly shared with Myoporaceae, or has it descended instead from the family's probable sister lineage, the Leucophylleae (Scrophulariaceae) of Mexico and Central America? We examined the possibility that Bontia is indeed an outlying member of the Myoporaceae by sequencing the rpl16 intron of the chloroplast genome for 60 taxa representing all major morphological lineages within the family, and representatives of probable outgroups that include the Leucophylleae. The sequence data were partitioned based on the probable secondary structure of the Group II intron; partition categories were defined as stem, loop, and interceding sequence. Relative rate of base change per partition was estimated using the method of Vawter and Brown (1993). The method does not assume rate constancy and allows for base composition bias between taxa and secondary structure components; therefore, relative rates of substitution can be compared between sequence partitions to study the amount of mutation occurring in stem, loop, and interceding sequence. We present the results of this partition study and the phylogeny estimate based on this data set. In this topology, Myoporaceae is monophyletic, Leucophylleae is sister to Myoporaceae, and Bontia is derived from within Myoporaceae. The results suggest that the distribution of Bontia is due to dispersal from an Australian ancestral lineage.

Eremophila is the largest genus in the plant tribe Myoporeae (Scrophulariaceae) and exhibits incredible morphological diversity across the Australian continent. The Australian Aboriginal Peoples recognize many Eremophila species as important sources of traditional medicine, the most frequently used plant parts being the leaves. Recent phylogenetic studies have revealed complex evolutionary relationships between Eremophila and related genera in the tribe. Unique and structurally diverse metabolites, particularly diterpenoids, are also a feature of plants in this group. To assess the full dimension of the chemical space of the tribe Myoporeae, we investigated the metabolite diversity in a chemo-evolutionary framework applying a combination of molecular phylogenetic and state-of-the-art computational metabolomics tools to build a dataset involving leaf samples from a total of 291 specimens of Eremophila and allied genera. The chemo-evolutionary relationships are expounded into a systematic context by integration of information about leaf morphology (resin and hairiness), environmental factors (pollination and geographical distribution), and medicinal properties (traditional medicinal uses and antibacterial studies), augmenting our understanding of complex interactions in biological systems., (© 2021 The Authors. The Plant Journal published by Society for Experimental Biology and John Wiley & Sons Ltd.)