The vascular bundle
concentration is the highest on the top part.
In general, the vascular bundles
are a little larger and less numerous per unit area, whereas parenchyma cells are unlignified in the Tight' zones, in contrast to the bundles and parenchyma in the 'dark' zones.
Leaf vascular bundle
penetration by SB has been previously reported in only 2 species of scales (Heriot 1934; Washington & Walker 1990).
Ogura (1972) finds such development of the vascular bundle
in Onoclea, Woodsia and Athyrium, and calls it the "Onoclea form.
These authors showed that five following characters are likely to be useful for comparison between and within subfamilies: a) whether the inner integument is thick or thin; b) the presence or absence of vascular bundles
in the inner integument; c) whether ovules or seeds are pachychalazal or not; d) whether seeds are arillate or not; and e) whether an exotegmen is fibrous or not.
These activities widen the more peripheral part of each of the medullary vascular bundles
with the secondary tissues to impart a wedge shape, the narrow end of which is occupied by primary xylem elements (Fig.
Flagellaria (Flagellariaceae) also lacks silica in the epidermis, but possesses small, irregular silica bodies above and below the leaf vascular bundles
, associated with the fibres of the vascular bundle
sheaths (Tomlinson, 1969).
5b-e) and are irrigated by a single vascular bundle
The objectives of this present study were to establish the number and distribution of the vascular bundles
in the different parts of rachis divisible into proximal, middle and distal segments through which food was supplied to individual differentially growing grains in aforementioned positions of spike and correlate the same with their innate natures.
Hence, it appeared that there was a direct positive correlation between reductions in the size of central vascular bundle
with the fertility of a spikelet as well as its grains capacity to grow.
the disc of insertion of floret four (F4) showed that four sub-vascular bundles
were available to it (Figure 4E and F) and their size were significantly smaller than vascular bundle
in basal florets.
Marginal rib lacking a vascular bundle
or fibrous bundle.
Median veins free, equidistant; OS surrounding vascular bundle
surrounds each vascular bundle
, which contains several large xylem
Fibers form vascular bundle
sheaths or caps over phloem, and sometimes xylem (Table II).