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.
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TL;DR: LM, SEM and TEM observations document similar palynological features for paleo- and neotropical species of Anaxagorea, offering convincing proof for the sometimes questioned systematic and phylogenetic coherence of the widely disjunct S. & C. Asian members of the Fusaea subfamily.
Abstract: LM, SEM and TEM observations document similar palynological features for paleo- and neotropical species ofAnaxagorea. Pollen grains are solitary, heteropolar, ellipsoidal to globose, and broadly sulcate. The exine consists of a smooth and microperforated tectum, a granular to “protocolumellar” infratectal layer, and sometimes an initial, not foliated basal layer. The intine is stratified and tends to extrude with its considerably swelling alveolarfibrillar outer layer through the aperture, already inside the unopened pollen sacs. This appears as a new and irreversible harmomegathic mechanism, limited toAnaxagorea, Meiocarpidium and possibly otherAnnonaceae. These palynological data are discussed and coordinated with those from gross-morphological, anatomical, karyological, phytochemical and other studies. All this offers convincing proof for the sometimes questioned systematic and phylogenetic coherence of the widely disjunct S. & C. American and SE. Asian members ofAnaxagorea. Furthermore, a broad comparison with otherAnnonaceae genera demonstrates somewhat closer links ofAnaxagorea with several small and relictual African genera, i.e.Meiocarpidium andPolyceratocarpus, but alsoLettowianthus andPiptostigma;Cleistopholis andAmbavia are more isolated. These genera which exhibit many “primitive” features are provisionally arranged under “tribe I” of the so-called “Fusaea subfamily”. There are loose affinities with “tribe II”, an assembly of more advanced and widespread, often proliferating generic groups, including the S. AsianCananga, the pantropicalXylopia (withPseudannona from Mauritius), a possible link toAnaxagorea and “tribe I”, and the S. AsianGoniothalamus (with the AustralasianRichella s. str. and the W. AfricanNeostenanthera andBoutiquea); the neotropicalFusaea andDuckeanthus apparently are more remote. Because of relationships to several otherAnnonaceae groups and difficulties with its circumscription and definition, the maintainance of the “Fusaea subfamily” as a whole appears questionable.
27 citations
01 Jan 1981
TL;DR: Values in excess of 4.5% N may signify the presence in a tissue of concentrated forms of protein, such as the chloroplastic proteins of leaves and the protein bodies of seeds and certain other reserve organs.
Abstract: Dry matter of plants contains a relatively constant proportion (38–46%) by weight of carbon and an amount of nitrogen (1–7%) which varies widely with plant species and with the type and age of plant from which it is derived. As shown in the examples given (Table 1) , levels of N in dry matter tend to be higher in shoots than in roots, and, within shoots, to be higher in leaves than in stems and usually highest in shoot apices, young leaves and fruits. Values in excess of 4.5% N may signify the presence in a tissue of concentrated forms of protein, such as the chloroplastic proteins of leaves and the protein bodies of seeds and certain other reserve organs. In mature seeds of legumes such as soybean (Glycine max) , the cotyledons may contain 40% or more of their dry matter as protein, with N comprising up to 7% of the dry weight. Roots rarely store protein to such a high level even when forming storage tap roots or tubers, the value of 11% protein in fresh weight recorded for root tubers of winged bean (Psophocarpus tetragonolobus) (29) being probably close to the maximum and well above the average attained by root crops.
27 citations
TL;DR: In this paper, a possible explanation for the presence of bark hearths in funerary context is proposed, suggesting it might be a symbolic parallel with the quotidian: the potency and power of transformation of bark as a fuel would be regarded in a spiritual level, achieving the transformation of the body soul in the revered soul.
27 citations
TL;DR: Observations of Austrobaileya scandens indicate that first angiosperms were woody plants that exploited wet, relatively dark and disturbed habitats and the establishment and persistence in forest understory habitats.
Abstract: Austrobaileya scandens, the sole species of the family Austrobaileyaceae, has been the subject of renewed interest following its placement near the root of the extant angiosperm phylogenetic tree. We present field observations on the growth habit, leaf anatomy, and physiological performance (photosynthesis and stem xylem hydraulics) of Austrobaileya from a premontane rain forest in northern Queensland. Austrobaileya scandens appears to possess functional characters that are commonly associated with flowering plants and ferns adapted to low light, including absence of palisade mesophyll tissue, low leaf photosynthetic rates, and possibly strong reliance on vegetative reproduction for recruitment. Also in line with many but not all shade‐tolerant species, the photosynthetic apparatus of A. scandens expressed little physiological ability to upregulate CO2 assimilation rate to increased light availability under greenhouse conditions. Broadly, these features appear to contribute to increasing the collection of...
27 citations
Cites background from "Anatomy of the Dicotyledons."
...Also, twining and scrambling viny growth habits occur frequently in the Austrobaileyales, as represented by Trimenia (formerly the two Piptocalyx species), Kadsura, and Schisandra (Metcalfe 1987)....
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...2F; Bailey and Swamy 1949; Terashima and Saeki 1983; Metcalfe 1987; Vogelmann and Martin 1993; DeLucia et al. 1996; Vogelmann et al. 1996; Smith et al. 1997)....
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...Additional measurements on the comparative stem hydraulic characteristics of angiosperm trees, shrubs, and lianas that co-occur with Austrobaileya in the understory as well other liana taxa in the Austrobaileyales (Trimenia, Schisandra, and Kadsura species) would be useful in placing hydraulic properties measured for Austrobaileya in an appropriate environmental and phylogenetic context....
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...Austrobaileya forms the basal branch of a clade referred to as the ITA clade, or Austrobaileyales, which includes three other lineages, Trimenia, Illicium, and Schisandra-Kadsura (Mathews and Donoghue 1999; Qiu et al. 1999, 2000; Soltis et al. 1999; Graham and Olmstead 2000)....
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...Leaves of Austrobaileya are entire and leathery in texture and are produced in an opposite to subopposite, nonoverlapping pattern at nearly horizontal orientations, including on scandent shoots (Bailey and Swamy 1949; Metcalfe 1987; fig....
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TL;DR: Wood features that ally Polygonaceae with Plumbaginaceae include nonbordered perforation plates, storeying in narrow vessels and axial parenchyma, septate or nucleate fibres, vasicentric parenchema, pith bundles that undergo secondary growth, silica bodies, and ability to form successive cambia, which support molecular cladograms that show the three families near the base of Caryophyllales s.l.
27 citations