An extinct kind of asymmetric samara occurs in the Eocene of Colorado, Utah, and Wyoming. The distinctive winged fruits were attributed to Anacardiaceae by Roland Brown in the 1920s and 1930s and ...were placed in the fossil genus Anacardites. However, that generic name, based on leaves from the Oligocene of France described a century earlier by Saporta, is inappropriate for these fruits. The samaras, which were not previously described in detail, are pedicellate, with a scar of hypogynous perianth and disk, and are nonschizocarpic, with an elliptical single-seeded endocarp and a lateral wing supplied with arching subparallel venation. We recognize these fruits as an extinct genus, Barkleya gen. nov. Although morphologically unique, the fruits share some characters in common with samaroid fruits of subfamily Anacardioideae, including Amphipterygium, Faguetia, Loxopterygium, Orthopterygium, and Schinopsis. We also provide an emended diagnosis for Rhus nigricans foliage and speculate, on the basis of co-occurrence and shared familial relationships, that the fruits of Barkleya schinoloxus (RW Brown) comb. nov. were produced by the same plant, which was a common element of the early to middle Eocene Green River flora.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
A robust generic classification for Amaryllidaceae has remained elusive mainly due to the lack of unequivocal diagnostic characters, a consequence of highly canalized variation and a deeply ...reticulated evolutionary history. A consensus classification is proposed here, based on recent molecular phylogenetic studies, morphological and cytogenetic variation, and accounting for secondary criteria of classification, such as nomenclatural stability. Using the latest sutribal classification of Hippeastreae (Hippeastrinae and Traubiinae) as a foundation, we propose the recognition of six genera, namely Eremolirion gen. nov., Hippeastrum, Phycella s.l., Rhodolirium s.str., Traubia, and Zephyranthes s.l. A subgeneric classification is suggested for Hippeastrum and Zephyranthes to denote putative subclades. In Hippeastrum, we recognize H. subg. Hippeastrum and H. subg. Tocantinia. In Zephyranthes, Z. subg. Eithea, Z. subg. Habranthus, Z. subg. Myostemma (= core Rhodophiala clade), Z. subg. Neorhodophiala subg. nov., and Z. subg. Zephyranthes are recognized. Descriptions, synonymy, taxonomic keys, and new combinations are provided for each genus and subgenus.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NMLJ, NUK, OILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK
Newly investigated leafy twigs bearing axillary fruits from the Eocene Parachute Creek Member of the Green River Formation in eastern Utah, USA, have provided more information on the species ...previously attributed to the Proteaceae as Banksia comptonifolia R.W.Br. The leaves are simple, estipulate with short petioles, and elongate laminae with prominent angular nonglandular teeth. The laminae have a thick midvein and pinnate craspedodromous secondaries, and are distinctive in the presence of a thick, often coalified, marginal rim. Vegetative and reproductive buds occur in the axils of the leaves. These features indicate that the species belongs to Palibinia Korovin—an extinct Eudicot genus previously known only from the Paleogene of Asia and Europe. Small pedicellate ovoid fruits 1.5–2.2 mm wide are borne in fascicles of three and are seen to be capsules with four apical valves. Despite the specific epithet referring to similarity of the foliage to that of Comptonia (Myricaceae), the fasciculate inflorescence organization with axillary flowers is quite distinct from the catkins characteristic of that family. Assignment to Banksia or other Proteaceae with complex inflorescences and follicular fruits is also problematic. Additionally, MacGinitie′s transfer of the species to Vauquelinia of the Rosaceae is contradicted by the lack of stipule scars on the twig and by differences in leaf venation and floral morphology. We transfer the species to Palibinia comptonifolia (R.W.Br.) comb. nov., but its familial affinity within the Pentapetalae remains uncertain. This new occurrence augments records from the Paleogene of Turkmenistan, Kazakhstan, China, England, and Germany.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Premise of the study: The opuntias (nopales, prickly pears) are not only culturally, ecologically, economically, and medicinally important, but are renowned for their taxonomic difficulty due to ...interspecific hybridization, polyploidy, and morphological variability. Evolutionary relationships in these stem succulents have been insufficiently studied; thus, delimitation of Opuntia s. s. and major subclades, as well as the biogeographic history of this enigmatic group, remain unresolved. Methods: We sequenced the plastid intergenic spacers atpB-rbcL, ndhF-rpl32, psbJ-petA, and trnL-trnF, the plastid genes matK and ycfl, the nuclear geneppc, and ITS to reconstruct the phylogeny of tribe Opuntieae, including Opuntia s. s. We used phylogenetic hypotheses to infer the biogeographic history, divergence times, and potential reticulate evolution of Opuntieae. Key results: Within Opuntieae, a clade of Tacinga, Opuntia lilae, Brasiliopuntia, and O. schickendantzii is sister to a well-supported Opuntia s. S., which includes Nopalea. Opuntia s. s. originated in southwestern South America (SA) and then expanded to the Central Andean Valleys and the desert region of western North America (NA). Two major clades evolved in NA, which subsequently diversified into eight subclades. These expanded north to Canada and south to Central America and the Caribbean, eventually returning back to SA primarily via allopolyploid taxa. Dating approaches suggest that most of the major subclades in Opuntia s. s. originated during the Pliocene. Conclusions: Opuntia s. s. is a well-supported clade that includes Nopalea. The clade originated in southwestern SA, but the NA radiation was the most extensive, resulting in broad morphological diversity and frequent species formation through reticulate evolution and polyploidy.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Premise
Early Eocene ambers of the Cambay lignite in Gujarat, India, are well known for their diverse insect fauna and dispersed pollen, but the included flowers have received limited attention. The ...fossil record of Apocynaceae is relatively poor, and the distinctive floral characters of this family have not been recognized in the fossil record before.
Methods
Remains of tiny flowers in amber were studied by micro‐CT scanning, reflected light, and epifluorescence microscopy.
Results
Flowers of Maryendressantha succinifera gen. et. sp. n. have actinomorphic, pentamerous, tubular corollas 2.2–2.3 mm wide, and 1.7–2.1 mm deep with sinistrorse aestivation and androecia consisting of a whorl of five stamens attached by short filaments to the lower half of the corolla tube. Anthers are ovate, rounded basally and apically tapered with their connectives convergent with one another in a conical configuration. The pollen is globose, psilate, tricolporate, and very small (10–11 µm). The combined characters indicate a position within the grade known as subfamily Rauvolfioideae.
Conclusions
These fossils, as the oldest remains of Rauvolfioids, complement the fossil records of Apocynoid and Asclepioid fossil seeds from other regions, demonstrating that the Apocynaceae were well established by the early Eocene, mostly consistent with prior divergence estimates for the phylogeny of this family. Potential pollinators, also preserved in the Cambay amber, include mosquitos, gnats, small moths, and stingless bees.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Abstract
We present the oldest known occurrences of crown-group Trochodendraceae based on new material from the Palaeocene of Wyoming, USA. Two genera are recognized, Trochodendron and Eotrochion ...gen. nov. The fossil fruit of Trochodendron infernense sp. nov. is represented by a pedicellate, apically dehiscent capsular fruit composed of nine follicle-like units, each bearing a persistent convex style. The basal part is ornamented with numerous raised stamen scars. From the same deposits, Eotrochion is represented by infructescences, fruits and associated leaves. The infructescences are racemes of numerous apically dehiscent capsules, each with c. 14–16 styles, each with an underlying nectary and receptacles lacking stamen scars, but possessing a prominent perianth scar. A phylogenetic assessment of the modern species, plus representatives of four extinct genera of fossil Trochodendraceae based on available morphological characters, yields a favoured topology of Trochodendron(Eotrochion(Concavistylon kvacekii(C. wehrii (Pentacentron, Tetracentron))). A parsimony analysis of currently available characters indicates that C. wehrii renders Concavistylon non-monophyletic. Accordingly, we transfer it to Paraconcavistylon gen. nov., characterized by pendent, rather than erect infructescences. We also reconsider the extinct Nordenskioeldia (Late Cretaceous to Miocene), the prior placement of which in Trochodendraceae has been challenged, and we consider it to fall outside the crown group of the family.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
A new section,
Miconia
sect.
Menendezia
, is recognized, characterized, and assessed phylogenetically. The section includes three species:
M. angustifolia
,
M. biflora
, and
M. urbanii
. All three ...have fruits with constricted hypanthia, and traditionally were included within an extremely non-monophyletic
Tetrazygia
. The monophyly of the section is supported by molecular analyses and morphology (i.e., calyx teeth flattened parallel to the associated lobe and equaling to much longer than the calyx lobes, and possibly also hypanthium constricted and calyx tube regularly tearing between the lobes). In addition, the inflorescence branches are flattened, although this condition is only poorly developed in
M. angustifolia
.
Miconia urbanii
(incl.
M. stahlii
) and
M. biflora
are morphologically distinctive (i.e., as evidenced by their strongly flattened inflorescence axes, flowers with an elongate hypanthium and calyx lobes, large petals that are undulate on one side, and fully inferior, slightly to strongly 4-lobed ovary) and these characters are likely synapomorphic for the putative
M. urbanii
+
M. biflora
clade, which was recognized as the genus
Menendezia
by N. L. Britton. Species descriptions, nomenclatural information, specimen citations, and eco-geographical characterization for each of the three species are presented, along with an identification key. Section
Menendezia
is well supported as a subclade within the Caribbean clade of
Miconia
, a morphologically heterogeneous clade of ca. 160 species (out of a total of some 1900 species in the genus). Finally, the names
Calycogonium biflorum
,
Tetrazygia angustifolia
,
T. stahlii
, and
T. urbanii
are lectotypified.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Abstract
The Greater Antilles are renowned as a biodiversity hotspot and known to be geologically complex, which has led, in part, to the generation of organismal diversity in this area. One of the ...most species-rich montane groups within the Greater Antilles is the tribe Miconieae (Miconia s.l.) of the Melastomataceae, with ca. 325 species found there. The most diverse clade of Miconia in the Caribbean, the Caribbean clade, composes roughly half of that diversity, with an estimated 160 species, nearly all of which are endemic to the Greater Antilles. It is unclear how that diversity has been generated through time or where it originated, but we now have sufficiently well-sampled and robust datasets to test these patterns. Using a custom-built plastome dataset, we generated a robust phylogenetic hypothesis for 106 of the 160 Caribbean clade members and tested biogeographical patterns among the islands. Our results suggest that the Caribbean clade originated in the mid-Miocene, probably from a South American ancestor, and diversified substantially on the island of Cuba before repeatedly dispersing across other parts of the Greater Antilles, especially into nearby Hispaniola and then, to a lesser extent, into Jamaica, Puerto Rico and, finally, into the Lesser Antilles.
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