Certified Arborist Practice Exam

What distinguishes a fir tree from other tree types?

1. Flat single needles growing directly on the twig

2. Cones growing upward

3. Needles growing in pairs of two, three, and five

4. Trees with small flat seeds

The correct answer is: Cones growing upward

The defining characteristic that distinguishes a fir tree from other types of trees is that fir trees have cones that grow upward. This upward orientation of the cones is a unique feature among conifers, including the fir family (Abies), setting them apart from other genera where cones may hang down or be oriented differently. In contrast, flat single needles growing directly on the twig is a trait that can be found in several other conifers and does not exclusively identify fir trees. Additionally, needles that grow in pairs of two, three, or five are characteristic of other conifer species such as pines, which have different growth habits. Lastly, while some trees may produce small flat seeds, this description is too broad to specifically isolate fir trees since other tree species also produce flat seeds. Thus, the characteristic of upward-growing cones is a clear marker of firs, aiding in their identification compared to other tree types.