scholarly journals Foliar, nonstructural nectaries in the Marantaceae

1985 ◽  
Vol 63 (10) ◽  
pp. 1785-1788 ◽  
Author(s):  
Bruce K. Kirchoff ◽  
Helen Kennedy

Nonstructural, foliar nectaries have been found in two genera of the Marantaceae (Zingiberales). Two nectaries are located on each leaf, at the junction of the leaf sheath and petiole. Externally, they may be readily distinguished from the surrounding tissue by their lighter color and absence of hairs. Internally, they show no specifically differentiated nectariferous tissue. In most species, the location of the nectaries is correlated with the distribution of fiber bundles. In nonncctariferous regions these bundles lie directly beneath the epidermis, while in the region of the nectary they occur several cell layers beneath the epidermis. Nectar secretion takes place through stomates. The cells surrounding the substomatal cavity may play an important role in the process of secretion. The distribution of structural nectaries in the family is also discussed.

2020 ◽  
Vol 25 (2) ◽  
pp. 379-408
Author(s):  
Ashraf S. Elhalawany ◽  
Xiao-feng Xue ◽  
James W. Amrine Jr

Five new eriophyoid mites infesting weeds of the family Poaceae are described and illustrated from Egypt. They are Abacarus stagninis sp. nov. from Echinochloa stagnina (Retz.) P. Beauv., vagrants in grooves between veins on the upper leaf surface, causing discoloration of the leaves; and four new species from genus Aceria (A. echinochloae sp. nov., A. barnyardi sp. nov., and A. stagninis sp. nov.) from E. stagnina and E. crus–galli (L.) Beauv., and Aceria pennisetosa sp. nov., from Pennisetum purpureum Schumach. These species are vagrants underneath inner surface of the leaf sheath around stem and no symptoms were observed. However, A. barnyardi sp. nov. is a vagrant underneath inner surface of the leaf sheath around stem and are endoparasitic inside tissue of leaves causing rusted leaves.


1961 ◽  
Vol 39 (7) ◽  
pp. 1809-1816 ◽  
Author(s):  
Job Kuijt

In the taxonomically confused Loranthoideae of the Americas the genus Oryctanthus stands out as a distinctive entity. The following combination of characters is described in support of this contention:1. The genus is limited to continental parts of tropical America, with the sole exception of one species in Jamaica.2. Few epicortical roots are produced, and these at the base of the plant only.3. Stellate fiber-bundles and crystalliferous sclereids are present in foliage leaves.4. The spikes are swollen and bear sunken, sessile flowers.5. The pollen type is apparently unique in the family.


2020 ◽  
Author(s):  
Balkrishna Ghimire ◽  
Dong Chan Son ◽  
Dabin Yum ◽  
Jae Hyun Kim ◽  
Mi Jin Jeong

Abstract Background Fruit morphological characters have contributing useful taxonomic data and thus used to discriminate the species in different taxonomic rank. The fruit and seed morphology and anatomy in the family Ranunculaceae has been a long history and proved to be a great value for its phylogeny. Methods Achene morphology and pericarp anatomy of 12 taxa representing three genera (Anemone, Hepatica, and Pulsatilla) of tribe Anemoninae were investigated using microtome and light microscopy (LM) to evaluate taxonomic implications of achene characters. Results The achenes of Anemone were elliptical or obovoid and beaked, whereas the achene of Hepatica and Pulsatilla were obovoid and elliptical, respectively. Noticeable variations in both quantitative and qualitative features of achenes were observed among the species of three genera. One-way ANOVA indicated that the quantitative achene variables among the species were highly significant (P < 0.001). Pearson’s correlation coefficient also showed a significant correlation between different achene variables. The pericarp structure, particularly the number of cell layers and cell form in exocarp and endocarp seems to very useful for species delimitation in Amenome and Hepatica. The nature of endotesta could provide a substantial proof for sub-generic classification in Anemone. The UPGMA analysis also showed the utility of achene features for taxonomic groupings of the species within studied genera. Conclusion Although the sampling specimens represented a limited range of taxa the achene features and pericarp anatomy provide a reasonable source for the taxonomic treatment of studied genera within the tribe.


2006 ◽  
Vol 54 (6) ◽  
pp. 595 ◽  
Author(s):  
Jia Li ◽  
Xue-Lin Huang ◽  
Yue-Rong Wei ◽  
Xia Huang ◽  
Zhe Li ◽  
...  

The histological origin of organogenesis was studied during plant regeneration of banana (Musa AAA cv. Williams) via direct organogenesis from micro-cross-sections of the rhizome in modified Murashige–Skoog (MS) medium (including 10 µm 6-BAP, 1 µm IAA and 50 µm KN). The frequency of the organogenesis was dependent on the position from where the explant was cut. Generally, more adventitious shoots were obtained from explants cut from regions close to apical meristem. The origin of adventitious shoots was multicellular, from cell layers with active cell division in the epidermis of the rhizome axis. After 24 h of culture, a layer of epidermal cells close to the leaf sheath base was actively dividing, and as the time in culture increased, regions containing actively dividing cells became enlarged. By the fifth day of culture, regions of actively dividing cells covered the whole peripheral zone of cortex. Several meristemoid structures were formed from the peripheral zone of cortex after 7 days of culture. These structures developed into adventitious shoots by the ninth day of culture. Vigorous plantlets could be regenerated from the shoots when they were transferred to rooting medium containing MS basal salts supplemented with 30 g L–1 sucrose, 6.5 g L–1 agar, a vitamin/amino acid mixture, 1 µm NAA and 1 µm 6-BAP.


2020 ◽  
Vol 21 (3) ◽  
Author(s):  
ULFA ADZKIA ◽  
NARESWORO NUGROHO ◽  
ISKANDAR Z. SIREGAR ◽  
Lina Karlinasari

Abstract. Adzkia U, Nugroho N, Siregar IZ, Karlinasari L. 2020. Ultrastructure of royal palm (Roystonea regia) leaf sheath. Biodiversitas 21: 967-974. The royal palm (Roystonea regia (Kunth) F.Cook is one of the palm species that are many planted along the streets as part of urban landscapes. As biologically products, in nature they can self-cleaning with drop off their big leaves. The study aims to examine the morphological characteristics of ultrastructure and elemental content, crystallinity, as well as fibers derivation characteristics from the royal palm. The samples were taken out from leaf sheaths that divided into three sections along the width of i.e. outside, middle, and inside; in two conditions of leaf sheaths namely green and brownish-dry. The morphology structure and elemental content were observed by the Scanning Electron Microscopy (SEM) and the Energy Dispersive X-ray analysis (EDX), while the crystallinity was analyzed using X-ray diffraction (XRD), and fiber characteristics were measured to determine cell dimensions as well as to calculate Runkle ratio (RR), muhlsteph ratio (MR), coefficient of rigidity (CR), felting powder (FP), and flexibility ratio (FR). The diameter of palm fiber bundles was decreased from outside towards inside. The model of vascular tissue was rounded which located in the central region of the fiber bundles. The silicon content in the inside section was lower than those in the middle and outside sections. It was in line with the degree of crystallinity in the inside section which that higher than other sections. The highest degree of crystallinity was about 18 %. The fiber length of royal palm leaf sheath was in values around 6000 μm. However, the royal palm leaf sheath had thick fiber walls and thin lumen, as well as other fiber derivation characteristics of muhlsteph ratio, the coefficient of rigidity and the flexibility ratio, were in low-quality values. For that reason, the study provides information that the royal palm sheath was recommended as a composite reinforcing material.


2012 ◽  
Vol 64 (4) ◽  
pp. 23-34 ◽  
Author(s):  
Aneta Sulborska

Investigations of the micromorphology of flowers and the structure of nectaries in <i>Chamomilla recutita</i> L. (Rausch.) were carried out with the use of stereoscopic, light, scanning and transmission electron microscopy. Biseriate glandular trichomes consisting of 5-6 cell layers were found on the surface of the corollas of ray and disc florets. Accumulation of secretion within the subcuticular space was accompanied by degradation of trichome cells. Secretion release followed rupture of the cuticle in the apical part of the trichome. The ovary of the ray florets exhibited characteristic ribs covered with epidermis composed of radially elongated palisade cells. Nectariferous glands were present only in the disc florets. The ring-like nectary (93 × 163 µm; height × diameter) was located above the inferior ovary. The gland structure was formed by single-layer epidermis and 5-8 layers of specialised nectariferous parenchyma. Nectar was released via modified 15-20 µm wide stomata. The guard cells were slightly elevated above the surface of the other epidermal cells or were located slightly below them. The stomatal cells were characterised by small external and internal cuticular ledges. No vascular bundles were observed in the nectary. The gland was supplied by branches of vascular bundles reaching the style and ending at the nectary base. The nectariferous tissue was formed by isodiametric cells with a diameter of 11-20 µm. The cell interior was filled with electron dense cytoplasm containing a large nucleus, numerous pleomorphic plastids, mitochondria with a distinct system of cristae, Golgi bodies, ER profiles, and ribosomes. The plastid stroma was characterised by presence of pastoglobuli, intraplastid tubules, and lighter zones. Several small vacuoles were found in each cell. Plasmodesmata were visible in the walls of some cells. Lighter periplasmic space in which apoplastic transport of nectar might take place was observed between the plasmalemma and the cell wall. The presence of an osmiophilic substance in the intercellular spaces additionally corroborates this assumption.


Botany ◽  
2015 ◽  
Vol 93 (11) ◽  
pp. 769-781 ◽  
Author(s):  
Rosemeri Morokawa ◽  
Juliana Lischka Sampaio Mayer ◽  
André Olmos Simões ◽  
Luiza Sumiko Kinoshita

Apocynaceae is one of the largest families of angiosperms. Its representatives have flowers with relatively simple morphology, ranging from anthers free from the style head to more complex flowers in which the anthers are postgenitally united with the style head, forming a gynostegium, and those with a style head that is vertically differentiated into distinct functional regions. The aim of this study is to understand the morphology and secretory structures of Condylocarpon isthmicum (Vell.) A.DC. at different stages of development. This species, which is in the family Apocynaceae, has morphologically simple flowers. Flowers at four different stages of development were collected and processed for anatomical and histochemical analysis; floral anatomy was examined using light and scanning electron microscopy. The simplicity of the C. isthmicum flower morphology was contrasted with the complexity observed in the secretory structures at different stages of flower development. Four secretory structures were identified in this species: colleters, style head epidermal cells, nectariferous tissue, and an obturator. The colleters were observed in the bracts and bracteoles of the young inflorescences. The style head began the secretory phase in the pre-anthetic stage and remained in this phase until anthesis. The nectariferous tissue was secreted during anthesis, and the obturator was present only in post-anthetic flowers. We identified a nectary in the wall of the ovary, and we verified and described a new structure in the Apocynaceae, the obturator.


1988 ◽  
Vol 62 (03) ◽  
pp. 419-423 ◽  
Author(s):  
Baba Senowbari-Daryan ◽  
George D. Stanley

Two Upper Triassic sphinctozoan sponges of the family Sebargasiidae were recovered from silicified residues collected in Hells Canyon, Oregon. These sponges areAmblysiphonellacf.A. steinmanni(Haas), known from the Tethys region, andColospongia whalenin. sp., an endemic species. The latter sponge was placed in the superfamily Porata by Seilacher (1962). The presence of well-preserved cribrate plates in this sponge, in addition to pores of the chamber walls, is a unique condition never before reported in any porate sphinctozoans. Aporate counterparts known primarily from the Triassic Alps have similar cribrate plates but lack the pores in the chamber walls. The sponges from Hells Canyon are associated with abundant bivalves and corals of marked Tethyan affinities and come from a displaced terrane known as the Wallowa Terrane. It was a tropical island arc, suspected to have paleogeographic relationships with Wrangellia; however, these sponges have not yet been found in any other Cordilleran terrane.


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