Question

A vasculum has $300$ leaves. $15\%$ of these belong to Mustard, $20\%$ calotropin, $10\%$ to guava, $15\%$ to Sunflower & the remaining to Alstonia. If $6$ leaves are present at each node of Alstonia, what is the total number of nodes seen in the various twigs present in the vasculum?
a. 175
b. 165
c. 145
d. 155

Answer 1

A stiff container used by botanists to hold field samples viable for transport is a vasculum or a botanical box. The vasculum 's primary function is to move plants without crushing them and to preserve a calm, humid climate.

Complete answer:
Vascula are usually cylinders made of tinned iron and often lacquered iron, although examples of wood are known. Horizontally on a strap, the box was held so that plant specimens lay flat and lined with moistened fabric.

Now, as per data given,
Total leaves = $300$

A single leaf occurs in Mustard ($15\%$) and sunflower ($15\%$) at each node, i.e. alternative phyllotaxy, so $45$ and $45$ nodes respectively are nodes for them.
In Calotropis ($20\%$) and guava ($10\%$) plants, i.e. $30$ and $15$ nodes respectively, a pair of leaves form at each node.
Alstonia has whorled phyllotaxy ($40\%$), i.e. two leaves occur at a node and form a whorl, i.e. $20$ nodes.

Adding all the node numbers from above, i.e., ($45+45+30+15+20$) the total nodes are $155$.
Hence, the correct answer is option (D).

Additional information:
Traditionally, with a single room, British and American vascula were somewhat flat and valise-like, whereas continental specimens were more cylindrical and sometimes wider, with two separate compartments often. Access to the interior is through one (sometimes two) wide side lids that allow plants to be placed in and taken out without unnecessarily bending or distorting them. For wildflowers, which are often fragile, this is especially relevant. Few specimens from the early 20th century are made from sheet aluminium rather than tin, but otherwise follow the trend of the 19th century. Usually, the exterior is left rough, or lacquered green.

Note: The vasculum 's origins are lost in time, but may have originated from a tin candle-box of similar construction in the 17th century. Linnaeus referred to it as a vasculum dilletanum, a small container of Latin vasculum and dilletanum, referring to J.J. Linnaeus' friend and colleague at the Oxford Botanic Garden, Dillenius.