BACKGROUND:
Many plants can reproduce either
sexually (seeds) or vegetatively (asexual), utilizing other plant parts.
Whole plants can be grown from stems, leaves or roots, if the right
plant is chosen. The following are some suggestions that can be used to
illustrate vegetative reproduction.
Stems: Ivy, potato tubers,
bamboo and iris rhizome, bulbs of various kinds (bulbs are actually
modified shoots), crocus or gladiolus, corn, Philodendron, Monstera
(split-leaf philodendron), strawberry and spider plant offsets. (Many
others will grow, even hardwoods, but they take a lot of time and
effort.)
Roots: Japanese anemone,
Oriental poppy, trumpet creeper, blackberry, raspberry, lily of the
Nile, and any other plant that produces sprouts from roots. (The roots
you plant will show no visible growth buds, the buds develop after the
root cutting is planted.)
Leaves: Begonias, African
violets, various succulents, sansevieria, piggy back plant (if leaf has
plantlet), and Bryophyllum.
PROCEDURE:
- Instruct the students to bring a
variety of plant parts from home to demonstrate vegetative reproduction.
Have a few plants on hand yourself for kids who do not contribute and so
that you have a few that you know will work (see list above). Plant the
parts in soil or water and keep them moist, but not soggy as to avoid
rotting the plant part. Remember that not all parts of a plant can
sprout. So try and instruct students to bring in stems that look like
they may be sprouting "air" roots (i.e. ivy).
- Sprouting can take anywhere from a
few days (some kinds of leaves or stems in water) to a few weeks (some
tubers and rhizomes). It is best to keep the plants out of direct
sunlight. Instruct the children to guess which will be first and keep a
record of all the plants, since all the plants may not sprout. In most
cases, with the exception of stems, do not make the cuttings
"sit" in stagnant water, aeration will help promote growth.
- Use plastic wrap to cover the
roots, to keep plants and soil from drying out.
