Petioles Sentence Examples

The leaves are fan-shaped with parallel veins on long slender petioles.

The leaves are broader than in most willows, and are generally either deltoid or ovate in shape, often cordate at the base, and frequently with slender petioles vertically flattened.

These bodies, known technically as chioroplaIts, are found embedded in the protoplasm of the cells of the mesophyll of foliage leaves, of certain of the cells of some of the leaves of the flower, and of the cortex of the young twigs and petioles.

In some cases leaves, as in Iris, or leaf-like petioles, as in Australian acacias and eucalypti, have their plane of expansion parallel to the axis of the shoot, there is then no distinction into an upper and a lower face, but the two sides are developed alike; or the leaf may have a cylindrical or polyhedral form, as in mesembryanthemum.

Some petioles are long, slender and sensitive to contact, and function as tendrils by means of which the plant climbs; as in the l,' nasturtiums (Tropaeolum), clematis and c in others; and in compound leaves the midrib and some of the leaflets may similarly be transformed into tendrils, as in the pea and vetch.

Pitchers are formed either by petioles or by laminae, and they are composed of one or more leaves.

The roundish leaves, toothed on the margin, are slightly downy when young, but afterwards smooth, dark green on the upper and greyish green on the lower surface; the long slender petioles, much flattened towards the outer end, allow of free lateral motion by the lightest breeze, giving the foliage its well-known tremulous character.

A feature of interest in connexion with the phylogeny of cycads is the presence of long hairs clothing the scale-leaves, and forming a cap on the summit of the stem-apex or attached to the bases of petioles; on some fossil cycadean plants these outgrowths have the form of scales, and are identical in structure with the ramenta (paleae) of the majority of ferns.

The petiole was usually traversed by a single vascular bundle, hippocrepiform in section - a marked point of difference from the more complex petioles of recent Marattiaceae.

The petioles have a somewhat complex structure, the bundle often having, in transverse section, the form of an H; it has been proposed to subdivide the genus on the details of the petiolar structure.

The spirally arranged petioles (Myeloxylon) were of great size, and their decurrent bases clothed the surface of the stem; their (From structure is closely similar to that Studies.) of recent Cycadean petioles; in FIG.

The lozenge-shaped areas external to the axis of the stem represent the sections of petioles, some of which are shown in fig.

Cycads, but the ramenta, instead of having the form of long unicellular hairs like those on the petioles and bud-scales of existing species are exactly like the paleae or ramental scales characteristic of the majority of ferns.

A number of hairy linear bracts enclose the whole; internal to these occur 12 to 20 crowded pinnate leaves (sporophylls), with their apical portions bent over towards the axis of the flower, the bases of the petioles being fused laterally into a disk surrounding the base of the conical receptacle.

With this change, great durability is probably acquired; at least this is the case with the clasped petioles of Clematis vitalba.

This movement of the leaves would aid that of the internodes in bringing the petioles into contact with surrounding objects.

I gently rubbed with a thin twig the lower surfaces of two young petioles; and in 2 hrs.

Straight, thin, black lines of this length were now drawn from the bases of the short petioles along the hypocotyls Fig.

As soon as the confluent petioles protrude from the seed they bend down, as they are strongly geotropic, and penetrate the ground.

Each bears three pairs of lateral leaflets and a terminal one, all supported on rather long sub- petioles.

It has been suggested that the red pigment Anthocyan, which is found very commonly in young developing shoots, petioles and midribs, effects a conversion of light rays into heating ones, so facilitating the metabolic processes of the plant.

Other tendrils are adapted stems, branches or petioles but do the same job.

Rhododendron Lanatum - The young branches, both surfaces of the leaves, and the petioles are covered with a dull white or tawny tomentum; the sulphur-yellow flowers are 2 inches across.

The variety palmata has the branchlets and frequently the petioles red.

Vitis Romaneti - Has large leaves, differing from all the Vines in cultivation (except Spinovitis Davidi) in having the branches and petioles covered with bristles or stout hairs.

The true balsam poplar, or tacamahac, P. balsamifera, abundant in most parts of Canada and the northern States, is a tree of rather large growth, often of somewhat fastigiate habit, with round shoots and oblong-ovate sharp-pointed leaves, the base never cordate, the petioles round, and the disk deep glossy green above but somewhat downy below.