Guide To Collecting Herbarium Specimens In The Field PDF Download

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1899 edition. Excerpt: ... CHAPTER IV DIRECTIONS FOR PARTICULAR FAMILIES Methods with Cactaceae. -- At first sight nothing can appear more obdurate than certain cactacess. Many of them are beset with sharp, bayonet-like spines, their points directed simultaneously in several directions. No one touches them with impunity. In hedges they are the despair of poacher, scout, or soldier. They form an impenetrable trocha. The common prickly pear ( Opuntia), which has not these long, projecting spines, is armed with even more dangerous weapons. Where leaves should be are groups of needle-like prickles, dislodged at a touch, and filling the skin with their painful barbs. Again, the Cactacece are coarse, succulent, and, in bulk, unmanageable. One could hardly press a complete specimen, however small. Fortunately this is not required. In case of the Platopuntice the joints can be split and the soft interior removed. Again, the flowers may be sectioned, and the portions dried. When the species are cylindric the branches are split and most of the fleshy interior removed. It is then easily possible to flatten the resulting halves. The object in each case is to exhibit the prickly or spiny areolae. Treated thus, the specimens present no difficulties in drying. Longitudinal sections of Echinocactus are essential. It is important to display the relative distances of the areolae, and at the same time the sharpness or bluntness of the ribs. These sections should reach to the utmost extremities in order to show the very important designative character of the tomentum of the areolae. Count and record on the field-label the number of ribs. Mammilaria is treated somewhat differently. Large quarter sections are cut from the apex downwards. Remove as much as possible of the soft parts and...