This section is from the book "British Wild Flowers - In Their Natural Haunts Vol2-4", by A. R. Horwood. Also available from Amazon: A British Wild Flowers In Their Natural Haunts.
A meadow or pasture is perhaps for field work the most accessible type or habitat for purposes of teaching botany first-hand. As a rule, in most parts of the country permission need not be obtained for this or any other purpose, if it be a legitimate one, hence the advantage of studying the meadow from this one point alone.
There are generally public footpaths across meadows leading from one place to another, and these can always be used, each district usually having its own footpath maps, which should be secured as a guide to the topography of the district and to avoid trespassing. In general, meadows laid to grass must not in summer be entered, nor those that abut upon woods where game is preserved, and where there are coops with hens and young pheasants.
Care should also be taken to close every gate, as this is a frequent source of annoyance to farmers, as is also the breaking down of fences in going from one field to another. If these precautions are taken few farmers will make any objection to excursions across country, except in areas where game is preserved.
If in any particular district such common rights are not recognized it is advisable to obtain permission, which, as a rule, owners or occupiers will grant for such purposes.
A word should here be said as to the necessity of preserving wild plants, and protecting them from any possible chance of extermination by exercising, in the case of rare species, if it is desired to make collections, great care in picking plants in such a way as not to endanger their chance of perpetuating themselves, and where only a few plants are to be seen none should be picked.
Some remarks should be made as to collecting and observing, but only general directions can be given here. Reference should be made to the author's Practical Field Botany (Griffin & Co.) for full details on this subject.
Plants should be collected in a fresh state, and it should be settled beforehand whether they are for study merely or for preservation. As complete a specimen as can be found should be selected, and this should be a typical one without any abnormal characters.
Observations should be made on the spot, and for this reason the pupils should be provided with notebooks, pencils, sketching blocks, squared paper, materials for making maps, callipers for measuring, dissecting instruments of a simple kind, apart from those appliances, etc., that are required for definite survey work if such is undertaken on more scientific lines. For elementary work, of course, fewer and more simple appliances will be sufficient.