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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 distribution pattern of calcium oxalate crystals in the leaf, stem, and root of four Nigerian species of Aneilema was investigated and reported for the first time.
Abstract: The distribution pattern of calcium oxalate crystals in the leaf, stem, and root of four Nigerian species of Aneilema was investigated and reported for the first time. The histochemically localised crystals of calcium oxalate varied in shape and region of localisation depending on the vegetative part of these Aneilema species. In the leaf of these taxa, crystals were found in the basal cells of trichomes (A aequinoctiale, A. beniniense and A. umbrosum) and in the mesophyll region of the lamina. Variations in shape were apparent in the stem: rhomboidal (A. aequinoctiale and A. beniniense) and irregular (A. paludosum and A. umbrosum). The diversity in localisation and shape of calcium oxalate crystals among these investigated species of Aneilema is discussed in relation to their biological significance.

14 citations

Journal ArticleDOI
08 Apr 2011-Biologia
TL;DR: Comparative anatomical and micromorphological studies of the two Teucrium montanum and T. polium species show that both taxa are similar in stem anatomy and their leaves exhibit xeromorphy, however, trichome morphology on the stems and the leaves appear to have a taxonomic value in segregation of the pair.
Abstract: Teucrium montanum L. and T. polium L. are the two closest Teucrium L. species from sect. Polium (Mill.) Schreb in Turkey. In addition, they are sympatric for some part of their range in Turkey. In this study, comparative anatomical and micromorphological studies of the two species are carried out. They have been investigated by their leaf and stem anatomical features, as well as nutlet micromorphological characteristics. The results of anatomical studies show that the anatomical characters of both taxa are observed to be similar to the general features of the family Lamiaceae anatomy, except for lacking rich collenchyma at the corners. Both taxa are similar in stem anatomy and their leaves exhibit xeromorphy. However, trichome morphology on the stems and the leaves appear to have a taxonomic value in segregation of the two taxa. Light and scanning electron microscope studies on the nutlets also show that nutlet shapes, measures and surface micromorphologies are different in the two species. Whereas nutlet surfaces are bireticulate in both species, the nutlets are larger and primary sculpturing is more distinct in T. polium than in T. montanum. Moreover, the nutlets are oblong to oblong-ovoid and larger in T. polium, but ovoid and smaller in T. montanum.

14 citations

Journal ArticleDOI
TL;DR: To assess diversity in the order, pollen from 19 genera was examined with light and scanning electron microscopy and specimens of Gomphandra from continental Asia exhibited seven different pollen morphologies, suggesting that exine patterns may be useful for the recognition of species in that region.

14 citations

Journal ArticleDOI
TL;DR: Evidence taken in conjunction with the data obtained from anatomy, morphology, palynology, embryology and floral biology, support the separation of the two genera Peperomia and Piper into two different families under Piperales as Peperomiaceae and Piperaceae, as done by certain taxonomists.
Abstract: Fifty three taxa have been studied during the present investigation, including eight species of Piper and nine of Peperomia. In Piper chromosome numbers ranging from 2n=24 to 195 have been found and polyploidy has been shown to be an important factor in evolution. The species of Piper studied here have multiples of 13, except P. cubeba L.f. which is deep-seated for the genus. However in P. cubeba L.f. n=12 chromosomes may represent the basic set from which n=13 might have been derived and this number became deep-seated in the species of Piper, possibly due to selective advantage. All the species of Piper except P. cubeba L.f. show a gross uniformity in the karyotype. However, differences in the number of nucleolar chromosomes have been recorded.In Peperomia, eight taxa have shown 2n=22 chromosomes, whereas in P. nummularifolia H.B.K. and P. pellucida H.B.K. 2n=23 and 2n=44 chromosomes are seen respectively. In the genus Peperomia the basic set of n=11 chromosomes is pronounced. The karyotype is characterised by relatively larger chromosomes than that of the genus Piper. The species of Peperomia differ in minute details of karyotype, suggesting the role of minute structural alterations in evolution.Cytologically the two genera Peperomia and Piper are quite distinct from each other. These evidences taken in conjunction with the data obtained from anatomy, morphology, palynology, embryology and floral biology, support the separation of the two genera into two different families under Piperales as Peperomiaceae and Piperaceae, as done by certain taxonomists, with Peperomia repre-senting a primitive state in evolution.

14 citations