What is the primary distinguishing feature between pine and spruce needles?

The primary distinguishing feature between pine and spruce needles is that pines are typically found in bundles, while spruce needles grow individually from the twig. This bundling characteristic in pines is known as fascicles, where clusters of needles emerge together, usually in groups of two to five depending on the species. In contrast, spruce trees have sharp, single needles that are attached directly to the stem and are usually four-sided, which gives them a distinctive spiky appearance.

This feature is crucial for identification in the field, as it helps differentiate species within the conifer family. The other characteristics mentioned, while they may describe differences between certain pine and spruce species, do not serve as the definitive feature that separates the two groups in a general sense.