Anatomy of the Dicotyledons.
About: This article is published in American Midland Naturalist.The article was published on 1950-11-01. It has received 2511 citations till now.
Citations
More filters
TL;DR: Phylogenetic analyses using DNA sequences of the chloroplast genes rbcL and ndhF strongly support the inclusion of Oceanopapaver in a clade of former Tiliaceae, Grewioideae (Malvaceae s.l.).
Abstract: The monotypic genus Oceanopapaver is an endemic shrub found growing on serpentine soils in New Caledonia. Since the description of Oceanopapaver neocaledonicum by A. Guillaumin in 1932, five families have been suggested for it: Capparaceae, Cistaceae, Oceanopapaveraceae, Papaveraceae, and Tiliaceae. Phylogenetic analyses using DNA sequences of the chloroplast genes rbcL and ndhF strongly support the inclusion of Oceanopapaver in a clade of former Tiliaceae, Grewioideae (Malvaceae s.l.). Within Grewioideae, Oceanopapaver is nested within the pantropical genus Corchorus.
34 citations
TL;DR: This paper examines if leaf-feeding insects capable of deactivating defensive plant canals with canal cutting often have broad host ranges, and identifies 94 species of canal-cutting insects, including eight new canal cutters described in this paper.
Abstract: According to the escalation–radiation model of co-evolution, insect herbivores that acquire the ability to circumvent a plant defence enter a new adaptive zone and increase in species. How herbivore counter-adaptations to plant defences might lead to speciation is poorly understood. Studies of nymphalid butterflies suggest that the evolution of a broadened host range may be a critical step. This paper examines if leaf-feeding insects capable of deactivating defensive plant canals with canal cutting often have broad host ranges. A total of 94 species of canal-cutting insects were identified from the literature, including eight new canal cutters described in this paper. Only 27% of canal cutters with known host ranges are generalists that feed on plants in multiple families. The proportion of generalist canal cutters is similar or lower than estimates of generalists among phytophagous insects overall. Only five species, at most, of the canal-cutting generalists feed exclusively on plants with secretory canals. The paucity of generalists can be attributed in part to the considerable taxonomic distance separating canal-bearing plant families and to their corresponding chemical distinctiveness. The dependence of many canal-cutting species on host chemicals for defence would also favour specialization. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 96, 715–731.
34 citations
TL;DR: The existence of this fossil, and reports of the subtribe from the Eocene of Europe, indicate a South American-North American-European-southeast Asian paleodistribution suggesting that extinction in North America and Europe was the cause of the tribe's current disjunct distribution.
Abstract: Numerous megafossils of Lauraceae have been reported from the early Tertiary of North America, but the subfamilial affinities are usually not well understood due to the great morphological variability found in extant taxa. The flowers of Androglandula tennessensis gen. et sp. nov. Taylor, from the Middle Eocene Claiborne Formation, are six-parted, pedicellate, bracteate, and have stamens with paired basal staminal glands. The flowers have ethereal oil cells and paracytic stomates throughout. The fossil species has affinities with the subtribe Cinnamomineae, and this supports suggestions that the Middle Eocene climate of the southeastern U.S. was subtropical. The existence of this fossil, and reports of the subtribe from the Eocene of Europe, indicate a South American-North American-European-southeast Asian paleodistribution suggesting that extinction in North America and Europe was the cause of the tribe's current disjunct distribution. THERE ARE NUMEROUS reports of fossil Lauraceae from the late Cretaceous and early Tertiary of North America (LaMotte, 1952; Table 1). The fossils occur in Greenland, Vermont, and Tennessee in the east, throughout the Rocky Mountain region, and along the Pacific coast from California to Alaska. Many of the older reports incorrectly assign fossils to Lauraceae (Kostermans, 1957), but the more recent reports are better substantiated and the affinities of the fossils to the family are based on diagnostic characters. Unfortunately, more precise indications of the relationships within Lauraceae are difficult as many of the extant taxa lack clearly diagnostic or shared derived characters.
34 citations
TL;DR: The authors described the botanical identity and facies distribution of fossil charcoal from Middle to Late Cenomanian (90-94 Ma) fluvial to estuarine units at Pecinov quarry, near Prague, Czech Republic.
Abstract: The botanical identity and facies distribution of fossil charcoal is described from Middle to Late Cenomanian (90–94 Ma) fluvial to estuarine units at Pecinov quarry, near Prague, Czech Republic. Braided alluvial facies associations contain charred conifer woods (family Pinaceae) possibly derived from upland forest fires, and abundant charred angiosperm woods, flowers and inflorescences (families Lauraceae and ?Platanaceae) derived from riparian gallery forest fires (Unit 2). Retrogradational coastal salt marsh facies associations contain abundant charred conifer wood (families Cheirolepidiaceae and Cupressaceae/Taxodiaceae) derived from fires in halophytic backswamp forest, and rare pinaceous charred cones and lauraceous angiosperm wood washed downstream from fires further inland (Units 3–4). Progradational coastal facies associations within an estuary mouth setting contain abundant charred conifer wood (family Cupressaceae/Taxodiaceae), common taxodiaceous conifer and angiosperm leaves, fern rachises, and lycopsid stems derived from fires in mesic backswamp taxodiaceous forests and supra-tidal fern-lycopsid thickets (Unit 5). Growth rings in angiosperm and conifer woods, leaf physiognomy and computer models indicate that climate was equable, warm and humid, but that there was a short annual dry season; most fires probably occurred during these annual drought periods. The abundance of charcoal and the diversity of taxa preserved in this state indicate that nearly all plant communities were fire-prone. Physiognomically, the Pecinov flora resembles present-day seasonally-dry subtropical forests where fires are a common occurrence.
34 citations
Cites background from "Anatomy of the Dicotyledons."
...This wood type exhibits a very close similarity with charred wood specimens of Paraphyllanthoxylon-type from the mid-Cretaceous Potomac Group of eastern North America (Herendeen, 1991a), which are similar to present-day wood of the family Lauraceae (Metcalfe & Chalke, 1950; Metcalfe, 1987; Herendeen, Wheeler & Baas, 1999)....
[...]
...…very close similarity with charred wood specimens of Paraphyllanthoxylon-type from the mid-Cretaceous Potomac Group of eastern North America (Herendeen, 1991a), which are similar to present-day wood of the family Lauraceae (Metcalfe & Chalke, 1950; Metcalfe, 1987; Herendeen, Wheeler & Baas, 1999)....
[...]
TL;DR: The small vessel diameter and high vessel frequency in many epacrids are indicative of a high conductive safety to avoid embolism caused by freeze-thaw cycles, while the replacement of scalariform by simple vessel perforation plates and an increase in vessel diameter would suggest an increased conductive efficiency.
34 citations