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Journal ArticleDOI

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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Journal ArticleDOI
TL;DR: The presence of two obviously different forms of ruminate endosperm indicates that rumination arose twice within the family Scytopetalaceae, and the proposed inclusion of Asteranthos in the latter family is fully confirmed.

15 citations

Journal ArticleDOI
TL;DR: An emphasis on seed characters suggests placement of Stanmarkia in the Sonerileae which is here interpreted in a broad sense to include all genera previously assigned to the New World Bertolonieae and the Old World Oxysporeae.
Abstract: A new genus,Stanmarkia, is described from the volcanic highlands of western Guatemala and adjacent Chiapas, Mexico to includeS. medialis, comb. nov. andS. spectabilis, sp. nov. Among the Melastomataceae,Stanmarkia is distinguished by its 5-merous flowers, subequal stamens that lack prominently developed appendages or prolonged connectives, terete hypanthia, and clavate-cuneate seeds that have an enlarged excurrent arilloid raphe and a tuberculate seed coat. A gametic chromosome count ofn=40 is reported here forS. spectabilis. This count, which is clearly of polyploid origin, represents a new definitive number for the family. An emphasis on seed characters suggests placement ofStanmarkia in the Sonerileae which is here interpreted in a broad sense to include all genera previously assigned to the New World Bertolonieae and the Old World Oxysporeae. A consideration of other characters such as configuration of the ovary apex, capsule morphology, and androecial details also provides evidence for placement ofStanmarkia in the Merianieae.

15 citations

Journal ArticleDOI
TL;DR: The results presented here suggest that fructans are a trait in this family while the levan-type fructan prevail in Gomphrena species.
Abstract: Gomphrena marginata Seub. (Amaranthaceae) is an endemic species from Brazilian campos rupestres with a fructan accumulating underground reserve system. Analyses of high performance anion exchange chromatography (HPAEC-PAD) revealed the presence of the soluble carbohydrates glucose, fructose, sucrose, 1-kestose, 6-kestose, nystose and fructans with degree of polymerization (DP) up to approximately 40 fructose units. Data of 1H and 13C Nuclear Magnetic Resonance (NMR) spectroscopy, including Heteronuclear Single-Quantum Correlation (HSQC) and Heteronuclear Multiple-Bonds Correlation (HMBC) showed the presence of β (2,6) linkages, characteristic of the linear molecule of levan-type fructan(2,6). These results confirmed previous studies suggesting that the reserve carbohydrate in the underground system of this species was levan-type fructans, similar to that of G. macrocephala. Structural analyses of the thickened underground system using light microscopy revealed a mixed origin system consisting mainly of a gemmiferous tuberous root with the upper region formed by short branched stems, both presenting vascular cylinders with unusual growth patterns. Fructan spherocrystals were visualized under polarized light and scanning electron microscopy (SEM) mostly in the cortex and vascular cylinder in both thickened stem and root. In addition to data reported in the literature concerning the occurrence of fructans in the Amaranthaceae, the results presented here suggest that fructans are a trait in this family while the levan-type fructan prevail in Gomphrena species.

15 citations


Cites background from "Anatomy of the Dicotyledons."

  • ...This anomalous thickening is a common phenomenon in the Amaranthaceae (Metcalfe and Chalk, 1950; Menezes et al., 1969; Grosso, 2007; El-Ghamery et al., 2015; Sá et al., 2016) and Chenopodiaceae (Metcalfe and Chalk, 1950; Krumbiegel, 1998)....

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  • ...Numerous species of Amaranthaceae are used in folk medicine (Fank-de-Carvalho et al., 2012) and most of them present underground reserve systems with anomalous secondary growth (Metcalfe and Chalk, 1950) responsible for the thickness of the organ....

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  • ..., 2012) and most of them present underground reserve systems with anomalous secondary growth (Metcalfe and Chalk, 1950) responsible for the thickness of the organ....

    [...]

Journal ArticleDOI
TL;DR: The structural characters of the xylem rays and the intercellular space system of the pneumatophore suggest their possible involvement in water transport in the secondary Xylem.
Abstract: Sonneratia alba J. Smith is a fast-growing pioneer mangrove tree species, and woody pneumatophores are one of the main morphological characters distinguishing this species from other mangrove species. Xylem rays of the pneumatophores in S. alba were exclusively uni-seriate and homocellular with procumbent cells. Intercellular spaces developed mainly between rows of procumbent ray cells to form continuous canals along the pneumatophore radius. Short axial intercellular spaces were present at the end wall sites of spindle-like procumbent ray cells within the same row, and interconnected with the neighboring radial intercellular canals into an intercellular space network within the xylem rays. The radial intercellular canals of xylem rays were larger in the outer secondary xylem than in the inner secondary xylem of a pneumatophore, and in the underground part than in the aboveground part. Blind pits (unilateral pits) towards the radial intercellular canals developed in the radial walls of vessels and the transverse walls of ray cells. The blind pits of vessels were bordered and vestured, and arranged radially in two regular rows in larger radial intercellular canals, but in one row or diffusely in narrower canals. The structural characters of the xylem rays and the intercellular space system of the pneumatophore suggest their possible involvement in water transport in the secondary xylem. An intercellular space system did not occur in xylem rays of the cable roots and stems of this species.

15 citations

Journal ArticleDOI
TL;DR: The woods of the three species are similar and cannot be separated microscopically or macroscopically and there was no evidence to indicate that Pseudowintera once possessed vessels and subsequently lost them.
Abstract: Wood anatomy of Pseudowintera axillaris J. R. et G. Forst. (Dandy), P. colorata (Raoul) Dandy, and P. traversii (Buchan.) Dandy is described. Growth rings are indistinct to slightly distinct. Vessels are absent from normal wood and wound tissue. There was no evidence to indicate that Pseudowintera once possessed vessels and subsequently lost them. Axial parenchyma, which is diffuse, diffuse-in-aggregates, and boundary, occurs frequently. Trabeculae are recorded in two parenchyma strands. Rays are heterogeneous. Multiseriate rays are extremely large, and sometimes noded. Tracheids have alternate bordered pits with included lenticular pits mouths. Tori are absent from bordered pits. Spiral thickening and trabeculae are occasionally present. Pits to rays are similar to pits between tracheids, but usually smaller. The woods of the three species are similar and cannot be separated microscopically or macroscopically. A perforated tracheid was found in wound tissue of P. axillaris.

15 citations