Parts of a flower – dissecting Alstroemeria plant science lesson

Pink Alstroemeria flower with green leaf

Help students learn the parts of a flower by dissecting Alstroemeria, or Peruvian lilies in the classroom. This activity is a great hands-on way of observing and identifying flower parts including sepals, petals, stamens, stigma, and pollen. In this blog post you’ll also find links to a free recording sheet for an Alstroemeria dissection and lesson slideshow.

Before we get started, please note that Wonder at the World doesn’t provide risk assessments. For this activity, you may want to consider allergies (skin and hay fever) and that Alstroemeria can be toxic to animals and humans if ingested. You can read our disclaimer here.

Benefits of Alstroemeria

• Easy to locate and extract the different parts of the flower
• Easy to obtain – you can buy them in bunches at grocery stores
• Low cost (and each stem has several flowers)
• Less likely to stain clothes than larger lilies
• Long-lasting flowers so you can prep a few days before

What you need:

• A flower per student
• Depending on the age of your students you may wish to use tweezers/forceps, or small scissors. In my opinion, scalpels aren’t necessary for using this type of flower with younger students.
• Students will need somewhere to collect the various flower parts. This could be a simple sheet of paper, or shallow dish or paper plate. If you want to use my printable, you can download here.
• Magnifying glasses or microscopes

Dissecting the flower

Students could start by holding the stalk and observing the complete flower. Explain that they’ll be working from the outside in. They’ll need to handle the flower very carefully to keep the various parts intact as they are removed. For each part, you can discuss its appearance and function.

Leaf

Before you start with the flower, you might want students to take a look at the leaf. This can be carefully removed and children can observe the shape (long and thin) and the pattern of veins (running along the length of the leaf).

Function: to produce food for the plant via photosynthesis.

Sepals

The next parts to remove are the sepals. On Alstroemeria, these look like petals but are wider. They are the same color as the petals but may have a small amount of green on the outside. In other types of flower, the sepals may be completely green. Students will be able to find and remove 3 sepals.

Function:
The sepals enclose and protect the flower when it is in bud.

Petals

Next, students should locate the petals. These are narrower than the sepals and are patterned. There are 3 true petals that students should carefully remove at the base.

Function: Brightly colored or patterned petals attract insects to the flower to pollinate it.

Stamens

The stamens are made up of 2 parts – the long filament, with an anther at the end. Students should be able to locate 6 stamens. They may notice the tiny grains of pollen on the anthers.
Things to note: The stigma looks similar in shape to the filament – they’ll move on to this part later. I’ve noticed the outsides of the anthers can drop off easily so some may appear without their ‘caps’.

Function: The stamens are the male parts of the flower. They produce pollen.

At this point, students will be left with the pistil – the female plant parts comprising the stigma, style, and ovary.

Stigma and style

The style is a long, thin part of the flower that students will locate in the center of the flower. It looks a lot like a stamen by the end isn’t as narrow, or topped with an anther. At the top of the style is the stigma. I’ve noticed that in older flowers, the stigma becomes more prominent, branching out into 3 parts.

Function: The stigma collects pollen. The style connects the stigma to the ovary.

Ovary and ovules

The swollen, green part at the base of the pistil is the ovary, with ovules inside. Students could carefully cut across the top of the ovary to view the ovules. These are very small so this part is worth looking at under a microscope. The ovules will develop into seeds after fertilization.

Recording

Students can record what they find in several ways:
• Arranging the flower parts on a printable sheet (see below). You could take a photo of each sheet for their science books. Glue or double-sided tape can hold the parts in place.
• Observational drawing the different parts – this can be done on the same printable sheet.
• Photograph each part

Download a free recording sheet

This simple sheet has 3 variations so you can pick the one that best suits you. Students can either arrange the flower parts on their sheet, or draw them in the boxes/
• Page 1: sepals, petals, stamens, stigma and style, ovary and ovules, pollen
• Page 2: sepals, petals, stamens, stigma and style, ovary, ovules
• Page 3: Blank boxes.