The Boraginales are now universally accepted as monophyletic and firmly placed in Lamiidae. However, a consensus about familial classification has remained elusive, with some advocating recognition of a single, widely variable family, and others proposing recognition of several distinct families. A consensus classification is proposed here, based on recent molecular phylogenetic studies, morphological characters, and taking nomenclatural stability into consideration. We suggest the recognition of eleven, morphologically well-defined and clearly monophyletic families, namely the Boraginaceae s.str., Codonaceae, Coldeniaceae fam. nov., Cordiaceae, Ehretiaceae, Heliotropiaceae, Hoplestigmataceae, Hydrophyllaceae, Lennoaceae, Namaceae, and Wellstediaceae. Descriptions, synonomy, a taxonomic key, and a list of genera for these eleven families are provided, including the new family Coldeniaceae (monogeneric) and Namaceae (segregated from Hydrophyllaceae and comprising Nama, Eriodictyon, Turricula, and Wigandia), the latter necessitating a revised circumscription of a more morphologically coherent Hydrophyllaceae. Keywords angiosperms; Boraginaceae; Boraginales; classification; family; plant taxonomy Boraginales Working Group • Families of Boraginales 503Version of Record TAXON 65 (3) • June 2016: 502-522 Boraginaceae in this traditional sense (Candolle, 1845; Bentham & Hooker, 1876;Gürke, 1893;Engler, 1898;Pilger & Krause, 1915) were subdivided into five subfamilies, namely Boraginoideae, Cordioideae, Ehretioideae, Heliotropioideae and Wellstedioideae. In pre-molecular times most scientists accepted this circumscription of Boraginaceae (e.g., Chadefaud & Emberger, 1960;Melchior, 1964b;Takhtajan, 1980Takhtajan, , 1997 Cronquist, 1981 Cronquist, , 1988Thorne, 1992), although some authors recognized one or the other subfamily at the family level. For example, Svensson (1925) andDi Fulvio (1978) removed Cordioideae, Heliotropioideae and Ehretioideae to Heliotropi aceae based on embryological studies, while Merxmüller (1960), Dahlgren (1980), and Takhtajan (1987) treated Wellstedioideae at the family level as Wellstediaceae. Conversely, Hoplestigmataceae, Hydrophyllaceae, and Lennoaceae were generally accepted as distinct families. However, the close relationships of these taxa to traditional Boraginaceae has been widely acknowledged by several authors (e.g., Jussieu, 1789; Baillon, 1891;Peter, 1893;Svensson, 1925; Chadefaud & Emberger, 1960; Melchior, 1964a, c;Takhtajan, 1980; Cronquist, 1981 Cronquist, , 1988. For example, Baillon (1891) defined the Boraginaceae as comprising nine series, which included both Boraginaceae and Hydrophyllaceae in their traditional circumscriptions. Chadefaud & Emberger (1960) considered Boraginaceae, Hoplestigmataceae, Hydrophyllaceae, and Lennoaceae to form a natural group within the order Tubiflorales. Takhtajan (1980) included these same families in the suborder Boraginineae.On the other hand, three groups historically associated to Boraginaceae have been clearly sho...
Boraginaceae s.str. is a subcosmopolitan family of 1600 to 1700 species in around 90 genera, and recent phylogenetic studies indicate that the infrafamilial classification as currently used is highly obsolete. The present study addresses the relationships of the major clades in Boraginaceae s.str. with an emphasis on monophyly of, and relationships between previously recognized clades and the position of various unplaced genera such as Afrotysonia, Anoplocaryum, Brachybotrys, Chionocharis, Craniospermum, Thyrocarpus, and Trigonocaryum using three plastid markers and a taxon sampling with four outgroup and 170 ingroup species from 73 genera. The phylogeny shows high statistical support for most nodes on the backbone and within individual clades. Echiochileae are confirmed as sister to the remainder of Boraginaceae s.str., which, in turn, fall into two well‐supported clades, the Boragineae + Lithospermeae and the Cynoglosseae s.l. The latter is highly resolved and includes the Lasiocaryum‐clade (Chionocharis, Lasiocaryum, Microcaryum) and the Trichodesmeae (Caccinia, Trichodesma) as sister to the remainder of the group. Rochelieae (formerly the Eritrichieae s.str., also including Eritrichium, Hackelia, and Lappula) form a poorly supported polytomy together with the Mertensia‐clade (also including Anoplocaryum, Asperugo, and Memoremea) and the Omphalodes‐clade. The enigmatic genus Craniospermum (Craniospermeae) is sister to an expanded Myosotideae (also including Brachybotrys, Decalepidanthus, Trigonocaryum, and Trigonotis) and these two clades are in turn sister to the Core‐Cynoglosseae, in which Afrotysonia glochidiata and Thyrocarpus sampsonii are included. Core‐Cynoglosseae again fall into two pairs of well‐supported subclades. The majority of generic placements are now resolved satisfactorily and the remaining phylogenetic questions can be clearly delimited. Based on the extensive phylogenetic data now available we propose a new infrafamilial classification into three subfamilies and 11 tribes, representing a consensus among the participating authors, according to which major clades are renamed.
Plants with a native (i.e., naturally occurring or nonanthropogenic) American amphitropical disjunct (AAD) distribution, occurring on both sides of, but not within, the American tropics, have long been recognized as a repeating biogeographic pattern found in a number of plant groups (
Early angiosperm evolution, beginning approximately 140 million years ago, saw many innovations that enabled flowering plants to alter ecosystems globally. These included the development of novel, flower-based pollinator attraction mechanisms and the development of increased water transport capacity in stems and leaves. Vein length per area (VLA) of leaves increased nearly threefold in the first 30-40 million years of angiosperm evolution, increasing the capacity for transpiration and photosynthesis. In contrast to leaves, high water transport capacities in flowers may not be an advantage because flowers do not typically contribute to plant carbon gain. Although flowers of extant basal angiosperms are hydrated by the xylem, flowers of more recently derived lineages may be hydrated predominantly by the phloem. In the present study, we measured leaf and flower VLA for a phylogenetically diverse sample of 132 species from 52 angiosperm families to ask (i) whether flowers have lower VLA than leaves, (ii) whether flowers of basal angiosperm lineages have higher VLA than more recently derived lineages because of differences between xylem and phloem hydration, and (iii) whether flower and leaf VLA evolved independently. It was found that floral structures had lower VLA than leaves, but basal angiosperm flowers did not have higher VLA than more derived lineages. Furthermore, the independent evolution of leaf and petal VLA suggested that these organs may be developmentally modular. Unlike leaves, which have experienced strong selection for increased water transport capacity, flowers may have been shielded from such selective pressures by different developmental processes controlling VLA throughout the plant bauplan.
Subtribe Amsinckiinae, currently containing 13 genera and approximately 287 species, is a species‐rich group of the family Boraginaceae. Past studies assessing relationships had a limited sample size and generally weak support. Here we study phylogenetic relationships of Amsinckiinae using a large sample size and considerably more sequence data in order to evaluate the interrelationships of genera and clades within this group. Using high‐throughput, genome skimming sequencing of 139 samples of Amsinckiinae and four outgroup taxa, maximum likelihood and Bayesian analyses of separate plastome, cistron, and mitochondrial datasets are presented. In almost all analyses the common ancestor of the Amsinckiinae gives rise to an Andersonglossum or to an Andersonglossum + Adelinia clade. Most genera, including Amsinckia, Eremocarya, Greeneocharis, Harpagonella, Oreocarya, and Pectocarya, are consistently monophyletic with strong support. Plagiobothrys is confirmed to be non‐monophyletic, composed of three clades conforming to generic sections. Cryptantha is also non‐monophyletic, with most species within a strongly supported Cryptantha s.str. clade, but some nesting within Johnstonella or our Maritimae clade, all with strong support. Although genome skimming verifies the monophyly of many genera and clades of Amsinckiinae, relationships among those clades and along the backbone of the trees remain uncertain, their elucidation possibly a factor of short branch lengths and likely requiring different types of molecular data. Our study may serve as a baseline for future work on the morphology, reproductive biology, and biogeography of the Amsinckiinae.
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