Baobabs (Adansonia) are a cohesive group of tropical trees with a disjunct distribution in Australia, Madagascar, and continental Africa, and diverse flowers associated with two pollination modes. We used custom-targeted sequence capture in conjunction with new and existing phylogenetic comparative methods to explore the evolution of floral traits and pollination systems while allowing for reticulate evolution. Our analyses suggest that relationships in Adansonia are confounded by reticulation, with network inference methods supporting at least one reticulation event. The best supported hypothesis involves introgression between Adansonia rubrostipa and core Longitubae, both of which are hawkmoth pollinated with yellow/red flowers, but there is also some support for introgression between the African lineage and Malagasy Brevitubae, which are both mammal-pollinated with white flowers. New comparative methods for phylogenetic networks were developed that allow maximum-likelihood inference of ancestral states and were applied to study the apparent homoplasy in floral biology and pollination mode seen in Adansonia. This analysis supports a role for introgressive hybridization in morphological evolution even in a clade with highly divergent and geographically widespread species. Our new comparative methods for discrete traits on species networks are implemented in the software PhyloNetworks. [Comparative methods; Hyb-Seq; introgression; network inference; population trees; reticulate evolution; species tree inference; targeted sequence capture.]

Previous research suggests that Gossypium has undergone a 5‐ to 6‐fold multiplication following its divergence from Theobroma. However, the number of events, or where they occurred in the Malvaceae phylogeny remains unknown. We analyzed transcriptomic and genomic data from representatives of eight of the nine Malvaceae subfamilies. Phylogenetic analysis of nuclear data placed Dombeya (Dombeyoideae) as sister to the rest of Malvadendrina clade, but the plastid DNA tree strongly supported Durio (Helicteroideae) in this position. Intraspecific Ks plots indicated that all sampled taxa, except Theobroma (Byttnerioideae), Corchorus (Grewioideae), and Dombeya (Dombeyoideae), have experienced whole genome multiplications (WGMs). Quartet analysis suggested WGMs were shared by Malvoideae‐Bombacoideae and Sterculioideae‐Tilioideae, but did not resolve whether these are shared with each other or Helicteroideae (Durio). Gene tree reconciliation and Bayesian concordance analysis suggested a complex history. Alternative hypotheses are suggested, each involving two independent autotetraploid and one allopolyploid event. They differ in that one entails an allopolyploid origin for the Durio lineage, whereas the other invokes an allopolyploid origin for Malvoideae‐Bombacoideae. We highlight the need for more genomic information in the Malvaceae and improved methods to resolve complex evolutionary histories that may include allopolyploidy, incomplete lineage sorting, and variable rates of gene and genome evolution.

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We assessed the validity of a recently described baobab species Adansonia kilima that was suggested to be a diploid occurring in both eastern and southern Africa at high elevations within the range of the well‐known tetraploid species A. digitata. We used a combination of phylogenetic analyses and statistical comparisons of various traits (e.g., flowers, stomata, pollen, chromosome counts) to test for the presence of two continental African baobab species. Ordination of the floral features of 133 herbarium specimens from across the natural range of A. digitata, including the putative type of A. kilima and other Tanzanian accessions as previously assigned A. kilima, revealed no distinct clusters of specimens. Likewise, stomatal size and density varied greatly across the specimens examined, with no clear bimodal pattern and no obvious association with altitude. The type specimen of A. kilima was found to have a chromosome number of 2n ≈ 166, showing it to be a tetraploid, like A. digitata. Phylogenetic analysis of the ITS region showed little resolution within the African baobab clade and a lack of distinction between the A. kilima type and A. digitata regional accessions. Among the 13 haplotypes detected, no distinct haplotype representing A. kilima was identified. Based on the data at hand we conclude that A. kilima is neither cytologically nor morphologically distinct and is here reduced to synonymy with A. digitata.

1. Plant biodiversity is often partitioned into taxonomic diversity (species composition and abundance), phylogenetic diversity (breadth of evolutionary lineages)

Phylogenetic and functional diversity are relevant for restoration planning, as they influence important ecosystem functions and services. However, it is unknown whether initial phylogenetic and functional diversity of restorations as planned and planted are maintained over time, that is, the extent to which diversity of the restoration planting is reflected in the diversity of the resulting plant community. Furthermore, in the tallgrass prairie, many restorations are planted from seed. Among-species variation in emergence and establishment affects the transition from seed mixes to realized plant communities in these restorations. We evaluated emergence and early establishment of experimental communities in a biodiversity plot experiment designed to test how phylogenetic and functional diversity influence restoration outcomes. We planted the same experimental communities starting from both seeds and plugs to assess differences in establishment. Our results suggest that phylogenetically and functionally diverse species mixes tend to produce phylogenetically and functionally diverse restored plant communities. After 3 years, experimental communities generally maintained their phylogenetic and functional diversity from seed and plug mixes to established vegetation, despite declines in species richness. While plots planted from seeds had on average 1.3 fewer species than plots planted from plugs, phylogenetic and functional diversity did not significantly differ between the two. Furthermore, most species exhibited no significant differences in percent cover when planted from seeds or plugs. Seeds are generally more cost-effective for restoration than plugs, and our results indicate these two establishment methods achieved similar biodiversity outcomes.

Plant productivity shapes how species compete and respond to stressors (Mahaut et al., 2020) and consequently how species are distributed in space, thereby shaping the assembly of plant communities. Productivity is traditionally estimated directly by measuring aboveground biomass and cover, but remote sensing is emerging as a less time-and resource-intensive tool (Heinsch et al., 2006; Yu et al., 2018). Estimating vegetation cover requires relatively little time and resources but considers growth in only two dimensions, ignoring vegetation height and density. Biomass estimates more directly measure total plant growth; however, collecting, drying, and weighing biomass are both resource intensive and destructive, limiting the practicality of biomass studies at large spatial and temporal scales. Recent developments in remote multispectral imagery and vegetation structure mapping have improved our ability to estimate plant productivity (Cerasoli et al., 2018; Fischer et al., 2019). Multispectral vegetation indices (VIs) are a collection of ratios and transformations of light reflectance intensities detected in certain spectral bands. They are based on the light that is reflected by vegetation, which is influenced by leaf health, density, and photosynthetic activity (Xue and Su, 2017); thus, VIs have emerged as an important tool for estimating plant community productivity (Wang et al., 2010; Cavender-Bares et al., 2017). Many VIs use the ratio of red to near-infrared reflectance because of the correlation between the contrast in the absorption of these bands and leaf health (Myneni et al., 1995). The normalized difference vegetation index (NDVI; Tucker, 1979) is the most commonly used VI. NDVI is based on the ratio of red and near infrared reflectance and is often applied in ecological studies (Pettorelli et al., 2005), where it has