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: The thermo-osmotically driven air stream that temporarily ventilates the plant body of Nelumbo nucifera, supplying rhizome and roots with oxygen, takes its way through interconnected canals and caverns using anatomical, pneumatic, and silicone casting methods to examine the structure of the two types of air canal diaphragms.
Abstract: The thermo-osmotically driven air stream that temporarily ventilates the plant body of Nelumbo nucifera, supplying rhizome and roots with oxygen, takes its way through interconnected canals and caverns. The course of this circulation, starting with the uptake of gas through leaf stomata and ending with its expulsion via the specialized navel (“central plate”) of the leaves, as well as organs regulating the circuit, were examined using anatomical, pneumatic, and silicone casting methods. The aerenchyma of the peltate leaf, closely paralleling the nervature, is divided into four separate domains: two mirroring lateral halves including halves of the central plate, and each half again separated into an adaxial (basal) and abaxial (distal) sector. Gas absorbed by the adaxial sectors flows through a definite pair of pipes down the petiole into three lateral pairs of the eight main tubes of the horizontal shoot. There it passes several nodes with adjoining leaves, where homologous ducts, arranged in series along the shoot, contribute to the gas flux in its basipetal course. A reverse gas flow, confined to another pair of cauline pipes and also arranged in series, enters in the nodes another pair of petiolar pipes that directly lead to the foliar central plates, where it is released through stomatal pores. These pores are three times as large as the laminal stomata and control the gas release by opening and closing. Each abaxial leaf sector is, apart from its ducts leading down the petiole, via a shortcut connected with the upstream pipes supplying the central plate, so that its air circuit, when active, is only intralaminar and does not join the entirety of the system. The question where, and how, the two downstreaming currents merge into the two upstreaming ones remains unresolved. The structure of the two types of air canal diaphragms, petiolar and nodal, are documented by SEM.
16 citations
TL;DR: The morphoanatomical characteristics of the leaves and the profiles of the essential oils of the morphotypes cidreira and melissa grown in the Medicinal Plant Garden of the Universidade Estadual de Santa Cruz, Ilheus, Bahia, Brazil, showed significant differences in terms of length, width and area.
Abstract: Lippia alba (Mill.) N.E. Br. ex Britton & P. Wilson, Verbenaceae, is widely used in traditional Brazilian medicine for the treatment of abdominal distress. The species exhibits considerable chemical and morphological diversity, and various chemotypes have been characterized. A comparative study of L. alba, has been carried out of the morphoanatomical characteristics of the leaves and the profiles of the essential oils of the morphotypes cidreira and melissa grown in the Medicinal Plant Garden of the Universidade Estadual de Santa Cruz, Ilheus, Bahia, Brazil. The mean plant height of cidreira was 1.80 m and the stems and branches were fairly erect, while melissa plants were smaller (1.60 m) and presented prostrate stems and branches. Although the leaf of the morphotypes look were similar, the mean values of length, width and area of the leaves of cidreira (respectively, 7.42 cm, 3.32 cm and 17.31 cm2) differed significantly from those of melissa (4.68 cm, 2.35 cm and 7.32 cm2). The morphotypes presented amphistomatic leaves with uniseriate epidermis on both surfaces. The mesophyll was dorsiventral, but in cidreira the palisade parenchyma was biseriate while in melissa it was uniseriate. Simple tector and capitate glandular trichomes were present on the adaxial and abaxial surfaces of the leaf blades of both morphotypes. Six distinct types of glandular trichomes could be distinguished: types I and II were present in both morphotypes, while type III was detected only in cidreira, and types IV to VI were present only in melissa. The two morphotypes also differed with respect to the composition of the essential oil, cidreira produced oil composed mainly of citral, while the oil from melissa was rich in citral, limonene and carvone.
16 citations
TL;DR: Light and first SEM observations on the pollen of A. annulata and A. rotundifolia indicate that the two species of the genus are clearly distinguishable from all other genera of the tribeStaticeae, and separate subtribal status for Aegialitis within the Plumbagineae is proposed.
Abstract: Light and first SEM observations on the pollen ofAegialitis indicate that the two species of the genus are clearly distinguishable from all other genera of the tribeStaticeae to whichAegialitis presently is relegated. Intraspecific exine or aperture dimorphism which appears frequently in this tribe, is not recorded in this genus.A. annulata andA. rotundifolia have distinct monomorphic pollen and show a great resemblance in exine features with the tribePlumbagineae, particularly species ofPlumbago. Considering these and other features, separate subtribal status forAegialitis within thePlumbagineae is proposed.
16 citations
Journal Article•
TL;DR: It was observed that the species have a perennial root and the stomatal index was calculated, which indicates that this species is a Euro-Siberian floristic element.
Abstract: Trachystemon orientalis (L.) G.Don (Boraginaceae), which is distributed in various habitats in the Black Sea region, was investigated morphologically and anatomically. The flowering branches, leaves and rhizomes of T. orientalis are used as food. This species is a Euro-Siberian floristic element. The genus Trachystemon D.Don is represented by one species in Turkey. In the morphological study it was observed that the species have a perennial root. The rhizome is blackish and 6-10 cm. The stem is 25-50 cm tall and erect. In anatomical studies, the cross and surface sections of the root, stem, rhizome, leaf and petiole were examined. In addition, the stomatal index was calculated.
16 citations
Cites background or result from "Anatomy of the Dicotyledons."
...Metcalfe and Chalk (1979) pointed out that there were both anomocytic and anisocytic stomata in the family Boraginaceae. It was stated by Özörgücü (1991) there was an anomocytic stomata in this family....
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...It was determined that the family Boraginaceae had glandular and eglandular hairs (Metcalfe & Chalk, 1979)....
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...Metcalfe and Chalk (1979) pointed out that there were both anomocytic and anisocytic stomata in the family Boraginaceae. It was stated by Özörgücü (1991) there was an anomocytic stomata in this family. Anomocytic stomata were also described in some Onosma species (Boraginaceae) (Akçin & Engin, 2001). In our study, the stomata was anomocytic. Stoma cells were more common on the lower epidermis. The same results were seen in Onosma species. The number of stomata was 14 ± 1 on the upper epidermis of the leaf and 42 ± 1 on the lower epidermis. The stomata index was 13.46 for the upper surface of the leaf and 35 for the lower surface. Metcalfe and Chalk (1979) pointed out that in many families, especially in Lamiaceae, the structure of the petiole is important in terms of taxonomy....
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...Metcalfe and Chalk (1979) gave information about the general anatomical characteristics of the family Boraginaceae....
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...Metcalfe and Chalk (1979) pointed out that in many families, especially in Lamiaceae, the structure of the petiole is important in terms of taxonomy....
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TL;DR: In this article, an anthracological analysis along with the 14C dating of charcoal fragments using accelerator mass spectrometry (AMS) was carried out to better understand the evolution of this region, ancient remains need to be analysed by all possible means.
16 citations