Old Man's Beard

Fact file

Old Man's Beard is a noxious plant. It threatens garden shrubs and native forests. It is a fast growing vine, which forms a smothering mass over trees and shrubs.

A single plant is capable of covering an area measuring 180 m² (e.g., 13 metres by 13 metres). It produces many seeds, which can stay alive in the ground for several years. A stem can grow up to 10 metres in one year.

Using the information from both the written text and the pictures complete the table below. Identify the special features of Old Man's Beard and explain how each helps it survive. For example the feature 'smothering mass' helps the plant survive because it covers and smothers other plants, using them for support and giving it the best position to get any sunlight.

	Special feature	How this special feature helps the plant to survive
i)
ii)
iii)

In what ways do these special features make Old Man's Beard a pest?

Diagnostic and formative information:

Pest plants have highly developed adaptations to ensure survival. Their ability to thrive puts other species at risk and this is why they are considered pests. These pest plants are all introduced plants.

For question a) common difficulties were:

Confusion over the meaning of the word 'noxious', some students interpreting noxious as 'poisonous'.
The lack of specific detail. See examples below of 2 different answers from students in the trial. The first shows a lack of detail - the second is an example of a detailed answer.

	Feature	How the feature helps
Answer 1	Seeds	Stay alive in the ground for years
Answer 2	It produces many seeds that can survive in the ground for many years	Because there are many seeds there is more chance that one will grow and because they can stay alive in the ground for several years they are more likely to end up growing even if conditions aren't right when the seeds are dropped.

Next steps:

Developing scientific vocabulary
An important part of a student's learning in science is the development of their knowledge of the vocabulary of science. Students need to develop the understanding that the word “feature” in science is used to refer to a characteristic or prominent trait. Students may be familiar with different meanings of the word in their every day worlds, e.g., a feature film, or a news feature, or an actor featuring in a film or someone having fine features. It is worthwhile drawing out these different meanings of words so that students develop the understanding that words can have different meanings in different situations. Further investigation into the use and correct meaning of the word 'noxious' may be needed too, depending on student responses to this resource.

Interdependence
Those plants that have special features that enable them to survive in a range of conditions are likely to become pests, especially when growing with less robust plants. This is especially likely when plants are introduced from a different ecosystem. When one species is very dominant it can lead to an imbalance in the ecosystem, affecting other plants and animals. A possible extension would be for students to investigate the specific impact of various pest plants on other species in the ecosystem.

Pest plants

Students could investigate the occurrence of pest plants in the local area, and contribute to activities designed to control or eradicate them. This would foster the development of the key competencies through science, in particular "participating and contributing" and "thinking".

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Old Man's Beard

Old Man's Beard