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NZ Plants


The following activities utilise a minimum of skills and equipment and are designed to enable the interested student to observe some aspects of plant reproduction.

Mosses and liverworts

Protonema can be cultured fairly easily by dusting fresh spores on moist soil of porous brick or clay.

Living antheridia of Funaria, Polytrichum, Breutelia, Bryum are good sources of antheridia. Collect material several days before it is to be studied, keeping it in a moist chamber, but not watered. Shortly before you want to observe it, remove the cover of the chamber to effect additional drying. If the stem tips are squeezed, the antheridia will be broken from their stalks, and will tranfer easily to a drop of water. Or, the antheridia may be dissected out into a drop of water.

If it is suspected that archegonia are present, begin removing the leaves on the stem somewhat below the apex. Remove leaf after leaf being careful not to break the stem. When only a few tiny leaves remain at the stem tip, examine with the dissecting or other low power microscope. There will be several leaf primordia surrounding one or more archegonia with numerous paraphases.

Capsules of mosses and liverworts, if collected when capsules are enlarged but not open, can be used to observe the release of spores. Placing the plants with attached sporophytes beneath the light of a dissecting microscope is all that is required to trigger capsule opening.

Regeneration of mosses can be studied by cutting up leaves and placing them on the surface of moist sand or soil. The growth of mold can be reduced if a dilute solution of household bleach is first used to surface sterilise the leaves and if the soil or sand is also sterilised by heat.


Observe a biological catapult in slow motion! 
(materials: hand lens, fertile, near-mature frond, glycerine, glass slides, coverslips and dissecting microscope) 
Select a fern frond with unopened sporangia. Experience with a hand lens will enable you to select a frond of the right age. Place a piece of the frond upside down and look for sori containing numerous tiny sporangia. Dissect out and mount a few fresh, ripe sporangia in a drop of glycerine on a microscope slide. Add a coverslip and observe spore discharge with a dissecting microscope at high magnification or with a microscope at a low magnification. Observe the sporangium opening in slow motion. Compare this with normal speed by mounting sporangia on a dry slide.

Cultivating fern spores 
(materials: fertile frond; Sphagnum moss, clay or plastic pot, fern spores, glass cover or polythene sheet ) 
(1) Place a near-mature fertile frond in a folded sheet of paper and keep in a warm dry position. Spores are shed in a few days and appear as a fine dust on the paper and may be stored in a vial in the refrigerator. 
(2) Sowing spores: Sterilise the Sphagnum and plant pot by pouring boiling water over them. Alternatively, place them in an oven for 30 minutes. The sterilisation will destroy fungi, algal spores, and unwanted fern spores. 
(3) Moisten the Sphagnum moss with sterilised water (this may be water which has been boiled and allowed to cool) and place in the pot. 
(4) Sow the fern spores directly on the Sphagnum and cover the plant pot with a glass sheet or plastic polythene. Place pot in adequate but NOT direct sunlight. 
(5) The spores should germinate in 4-6 weeks and after 6-12 months the first true fronds should appear.


Pollen cones 
These are usually located at lower levels of most pine trees. They emerge from buds in the spring as small, compact groups of 5-25 tiny cones. In the early spring, spores (with a single cell and no wings) will be found, but as spring progresses, pollen grains (with several cells and large wings) will be found. Cones of all stages are easy to dissect for observation of cone scales and sporangia using a dissecting microscope or hand lens, and spores or pollen grains under a compound microscope.

Ovule cones 
It is best to look for small trees or ones that are stunted due to exposure, as the ovule cones are found at higher levels and can be difficult to reach. In the early spring, small fleshy cones appear at the tips of branches. Observation with a hand lens will reveal pollen grains adhering to their surface. Dissection is difficult as the young cones are very fleshy and watery. Moving down the branch, you will come across ovule cones that are beginning their second season of growth. The cone can be broken in half by hand, exposing the scales and ovules. The location, orientation and appearance of the micropyle can be easily seen. If these same cones are collected toward the middle or end of the second growing season, ovules can be extracted. An understanding of ovule structure is obtained if the ovules are cut down three sides and gentle pressure applied to force the contents out. This separates the integument from the female tissue which in turn is surrounded by the thin megaspore membrane.

Seed germination 
Seeds can be collected or purchased and sown, and germination can be observed. Early stages are best seen using seeds sown on moist absorbent paper in petri dishes. For more prolonged observation, sow seeds in potting mix and keep moist.

Flowering plants

Stamen and microspores 
Any young flower (those of many monocots are suitable) will serve as a source of young stamens. If these are cut open and the contents gently squeezed out onto a microscope slide. If a coverslip is then added and slight pressure applied, the cells will spread out so that the stages of meiosis and pollen development can be followed.

The carpel and ovule 
Many vegetables are suitable for demonstrating carpels. Pea pods (or beans) and cucumber are especially good for carpel and ovule structure. Dissected ovules or transections of the carpel through the ovules, will reveal their structure.

By soaking seeds overnight they become soft and are more easily dissected. If they are germinated in soil or on moist paper, stages in seedling emergence can be observed.

Further links with information on activities

The Botanical Society of America.

The National Science Teachers Association. An educational website in the United States.