Introduction
A “key” is a systematic process of elimination. It will guide you through a series of choices and narrow down the selections until one selection remains.
Once you work through the key, it takes you to a description of the tree. Check the description and photographs against the plant sample. Does it match? If not, return to the key, looking for other possible options at various levels.
Characteristics used in this key are generic for the tree genus and species, assuming an environment conducive to good plant health. For plants under growth stress, leaf size may be different along with differences in coloration and texture. These factors could lead to a incorrect identification.
For tree identification, a small branch with leaves will be needed. Avoid sucker and watersprout growth as these may be atypical.
This key includes trees common to Colorado Front Range landscapes. However, it does not include all trees grown in the region.
Key to Conifer or Broadleaf Tree
A1. Does the foliage have a broad, flat blade? — Continue with this key
A2. Is foliage needle-like or scale-like? — refer to CMG GardenNotes #172, Identifying Conifers.
This online key was adapted from Identification Key for Woody Plants of the Pikes Peak Region by CSU Extension, El Paso County. This publication was developed by Linda Smith, El Paso County Extension Office for Colorado Master Gardeners.
Authors: Linda Smith (El Paso County Extension Office, retired), Christine Prins (Colorado State University), and David Whiting (Dept. of Horticulture & LA, Colorado State University)
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November 2025
