WEED STUDIES
In every locality there are about a dozen weeds that are particularly troublesome, and the pupils of Form III should be taught to identify these and to understand the characteristics which make each weed persistent.
To produce these results it will be necessary to have exercises such as the following:
1. The teacher exhibits a weed to the pupils and directs their attention to a few of the outstanding features of the plant.
2. The pupils are required, as a field exercise, to observe where the weed is abundant; and whether in hay field, pasture, hoe crop, or in grain. The pupils will bring specimens to the class.
3. Detailed study in the class of specimens of the weed brought by the pupils to find offensive odours and prickles, also the character of the leaves, flowers, seed pods, and seeds, including the means of dispersal; the underground parts, whether underground stem, tap-root, or fibrous root, and the value of the underground parts as a means of persistence.
4. The pupils make a collection of the weeds that have been studied. (See Plant Collection, page 39, in General Method.)
5. The pupils make collections of the seeds of the weeds that have been studied.
OBSERVATION LESSON ON WEED SEEDS
The seed of a weed should always be exhibited and studied in association with a fresh or a mounted specimen of the weed.
Each pupil should use a hand lens in examining the seed.
The pupils examine the seed of each species and describe it according to the following scheme:
NAME OF SEED
Colour:
Size: (in fractions of an inch)
Shape:
Details:
Occurrence:
The results of the pupils' study of the ox-eye daisy would then appear in the following form:
SEED OF OX-EYE DAISY
Colour: Black and greenish-white in stripes,
Size: One sixteenth of an inch,
Shape: Club-shaped,
Details: Grooved lengthwise, yellow peg in large end,
Occurrence: A common impurity in grass seed.