The submergence-tolerant species Rumex palustris (Sm.) responds to complete submergence by an increase in petiole angle with the horizontal. This hyponastic growth, in combination with stimulated elongation of the petiole, can bring the leaf tips above the water surface, thus restoring gas exchange and enabling survival. Using a computerized digital camera set-up the kinetics of this hyponastic...

The Trachycarpus fortunei palm is a good example of a palm with a large leaf blade supported by a correspondingly large petiole. The way in which the material and functional properties of the petiole interact is analysed using engineering and botanical methods with a view to understanding how the petiole functions from a structural standpoint. Initially, the histological aspects of the petiole ...

Essentially chlorophyll-free mitochondria from photosynthetic (leaf) and non-photosynthetic tissue (petiole) were isolated from spinach (Spinacia oleracea). Leaf mitochondria were found to contain more phosphatidylcholine than phosphatidylethanolamine compared with petiole mitochondria. Galactolipids were found in small and equal amounts (5 mol of galactolipids/100 mol of galactolipids and phos...

BACKGROUND AND AIMS Complete submergence is an important stress factor for many terrestrial plants, and a limited number of species have evolved mechanisms to deal with these conditions. Rumex palustris is one such species and manages to outgrow the water, and thus restore contact with the atmosphere, through upward leaf growth (hyponasty) followed by strongly enhanced petiole elongation. These...

The paper deals with pharmacognosy of Centella asiatica (L.) Urban, including its morphological, anatomical, chemical constituents and powder analysis. Stomata are mostly anisotricytic, isotricytic and few tetracytic. Sphaero-crystals of calcium oxalate are observed in palisade, spongy and ground parenchyma of leaf lamina, petiole and rhizome and absent in roots. Uniseriate flagellate conical h...

The impact of water deficit on stomatal conductance (g(s)), petiole hydraulic conductance (K(petiole)), and vulnerability to cavitation (PLC, percentage loss of hydraulic conductivity) in leaf petioles has been observed on field-grown vines (Vitis vinifera L. cv. Chasselas). Petioles were highly vulnerable to cavitation, with a 50% loss of hydraulic conductivity at a stem xylem water potential ...

A long-standing controversy exists regarding the laryngoscopic features associated with unilateral denervation of the external superior laryngeal nerve (ESLN). Recently, we modeled acute unilateral cricothyroid muscle paralysis by blocking the ipsilateral ESLN with lidocaine hydrochloride, and identified epiglottic petiole deviation to the side of paralysis during high-pitched voice production ...

Petiole sap N and K quick tests offer fast and accurate in-field analysis for N and K and have been calibrated for some vegetable crops in Florida. This paper summarizes 10 years of research conducted in Florida on petiole sap testing for N and K. Petiole sap nitrate-N and K concentrations correlated highly with wholeleaf N and K concentrations and decreased through the season for all vegetable...

The mean deltaD value of petiole water of Pterocarpus indicus Willd (deltaD = -9.0 +/- 2.5 per thousand, n = 3) was not significantly different from the mean value of stem water (-8.3 +/- 2.8 per thousand, n = 3). deltaD values of main vein water ranged from -11.1 to + 12.0 per thousand (n = 14) and increased along the main vein from petiole to the tip of leaves. Mesophyll water was highly enri...

Rumex palustris responds to complete submergence with upward movement of the younger petioles. This so-called hyponastic response, in combination with stimulated petiole elongation, brings the leaf blade above the water surface and restores contact with the atmosphere. We made a detailed study of this differential growth process, encompassing the complete range of the known signal transduction ...